printf - Page 6 - Developer IT

How to combine two 32-bit integers into one 64-bit integer?

- by Bei337

I have a count register, which is made up of two 32-bit unsigned integers, one for the higher 32 bits of the value (most significant word), and other for the lower 32 bits of the value (least significant word). What is the best way in C to combine these two 32-bit unsigned integers and then display as a large number? In specific: leastSignificantWord = 4294967295; //2^32-1 printf("Counter: %u%u", mostSignificantWord,leastSignificantWord); This would print fine. When the number is incremented to 4294967296, I have it so the leastSignificantWord wipes to 0, and mostSignificantWord (0 initially) is now 1. The whole counter should now read 4294967296, but right now it just reads 10, because I'm just concatenating 1 from mostSignificantWord and 0 from leastSignificantWord. How should I make it display 4294967296 instead of 10?

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socket connection failed, telnet OK

- by cf16

my problem is that I can't connect two comps through socket (windows xp and windows7) although the server created with socket is listening and I can telnet it. It receives then information and does what should be done, but if I run the corresponding socket client I get error 10061. Moreover I am behind firewall - these two comps are running within my LAN, the windows firewalls are turned off, comp1: 192.168.1.2 port 12345 comp1: 192.168.1.6 port 12345 router: 192.168.1.1 Maybe port forwarding could help? But most important for me is to answer why Sockets fail if telnet works fine. client: int main(){ // Initialize Winsock. WSADATA wsaData; int iResult = WSAStartup(MAKEWORD(2,2), &wsaData); if (iResult != NO_ERROR) printf("Client: Error at WSAStartup().\n"); else printf("Client: WSAStartup() is OK.\n"); // Create a socket. SOCKET m_socket; m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (m_socket == INVALID_SOCKET){ printf("Client: socket() - Error at socket(): %ld\n", WSAGetLastError()); WSACleanup(); return 7; }else printf("Client: socket() is OK.\n"); // Connect to a server. sockaddr_in clientService; clientService.sin_family = AF_INET; //clientService.sin_addr.s_addr = inet_addr("77.64.240.156"); clientService.sin_addr.s_addr = inet_addr("192.168.1.5"); //clientService.sin_addr.s_addr = inet_addr("87.207.222.5"); clientService.sin_port = htons(12345); if (connect(m_socket, (SOCKADDR*)&clientService, sizeof(clientService)) == SOCKET_ERROR){ printf("Client: connect() - Failed to connect.\n"); wprintf(L"connect function failed with error: %ld\n", WSAGetLastError()); iResult = closesocket(m_socket); if (iResult == SOCKET_ERROR) wprintf(L"closesocket function failed with error: %ld\n", WSAGetLastError()); WSACleanup(); return 6; } // Send and receive data int bytesSent; int bytesRecv = SOCKET_ERROR; // Be careful with the array bound, provide some checking mechanism char sendbuf[200] = "Client: Sending some test string to server..."; char recvbuf[200] = ""; bytesSent = send(m_socket, sendbuf, strlen(sendbuf), 0); printf("Client: send() - Bytes Sent: %ld\n", bytesSent); while(bytesRecv == SOCKET_ERROR){ bytesRecv = recv(m_socket, recvbuf, 32, 0); if (bytesRecv == 0 || bytesRecv == WSAECONNRESET){ printf("Client: Connection Closed.\n"); break; }else printf("Client: recv() is OK.\n"); if (bytesRecv < 0) return 0; else printf("Client: Bytes received - %ld.\n", bytesRecv); } system("pause"); return 0; } server: int main(){ WORD wVersionRequested; WSADATA wsaData={0}; int wsaerr; // Using MAKEWORD macro, Winsock version request 2.2 wVersionRequested = MAKEWORD(2, 2); wsaerr = WSAStartup(wVersionRequested, &wsaData); if (wsaerr != 0){ /* Tell the user that we could not find a usable WinSock DLL.*/ printf("Server: The Winsock dll not found!\n"); return 0; }else{ printf("Server: The Winsock dll found!\n"); printf("Server: The status: %s.\n", wsaData.szSystemStatus); } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2 ){ /* Tell the user that we could not find a usable WinSock DLL.*/ printf("Server: The dll do not support the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion)); WSACleanup(); return 0; }else{ printf("Server: The dll supports the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion)); printf("Server: The highest version this dll can support: %u.%u\n", LOBYTE(wsaData.wHighVersion), HIBYTE(wsaData.wHighVersion)); } //////////Create a socket//////////////////////// //Create a SOCKET object called m_socket. SOCKET m_socket; // Call the socket function and return its value to the m_socket variable. // For this application, use the Internet address family, streaming sockets, and the TCP/IP protocol. // using AF_INET family, TCP socket type and protocol of the AF_INET - IPv4 m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); // Check for errors to ensure that the socket is a valid socket. if (m_socket == INVALID_SOCKET){ printf("Server: Error at socket(): %ld\n", WSAGetLastError()); WSACleanup(); //return 0; }else{ printf("Server: socket() is OK!\n"); } ////////////////bind////////////////////////////// // Create a sockaddr_in object and set its values. sockaddr_in service; // AF_INET is the Internet address family. service.sin_family = AF_INET; // "127.0.0.1" is the local IP address to which the socket will be bound. service.sin_addr.s_addr = htons(INADDR_ANY);//inet_addr("127.0.0.1");//htons(INADDR_ANY); //inet_addr("192.168.1.2"); // 55555 is the port number to which the socket will be bound. // using the htons for big-endian service.sin_port = htons(12345); // Call the bind function, passing the created socket and the sockaddr_in structure as parameters. // Check for general errors. if (bind(m_socket, (SOCKADDR*)&service, sizeof(service)) == SOCKET_ERROR){ printf("Server: bind() failed: %ld.\n", WSAGetLastError()); closesocket(m_socket); //return 0; }else{ printf("Server: bind() is OK!\n"); } // Call the listen function, passing the created socket and the maximum number of allowed // connections to accept as parameters. Check for general errors. if (listen(m_socket, 1) == SOCKET_ERROR) printf("Server: listen(): Error listening on socket %ld.\n", WSAGetLastError()); else{ printf("Server: listen() is OK, I'm waiting for connections...\n"); } // Create a temporary SOCKET object called AcceptSocket for accepting connections. SOCKET AcceptSocket; // Create a continuous loop that checks for connections requests. If a connection // request occurs, call the accept function to handle the request. printf("Server: Waiting for a client to connect...\n"); printf("***Hint: Server is ready...run your client program...***\n"); // Do some verification... while (1){ AcceptSocket = SOCKET_ERROR; while (AcceptSocket == SOCKET_ERROR){ AcceptSocket = accept(m_socket, NULL, NULL); } // else, accept the connection... note: now it is wrong implementation !!!!!!!! !! !! (only 1 char) // When the client connection has been accepted, transfer control from the // temporary socket to the original socket and stop checking for new connections. printf("Server: Client Connected! Mammamija. \n"); m_socket = AcceptSocket; char recvBuf[200]=""; char * rc=recvBuf; int bytesRecv=recv(m_socket,recvBuf,64,0); if(bytesRecv==0 || bytesRecv==WSAECONNRESET){ cout<<"server: connection closed.\n"; }else{ cout<<"server: recv() is OK.\n"; if(bytesRecv<0){ return 0; }else{ printf("server: bytes received: %ld.\n",recvBuf); } }

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Scripting with the Sun ZFS Storage 7000 Appliance

- by Geoff Ongley

The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)> printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)> printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)> if (counter==10) ("." to run)> { ("." to run)> isTen=true; ("." to run)> } ("." to run)> printf("Counter is %d\n",counter);("." to run)> counter++; ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)> if (counter==10) ("." to run)> { ("." to run)> isTen=true; ("." to run)> break;("." to run)> } ("." to run)> printf("Counter is %d\n",counter);("." to run)> counter++; ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){ user=users[k]; run('select ' + user); var username=get('name'); var usage=get('usage'); var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)> run('select ' + shares[i]);("." to run)> var mountpoint=get('mountpoint');("." to run)> printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)> run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){ run('select ' + proj); shares=list(); printf("Project: %s\n", proj); for(j=0; j < shares.length; j++) { printf("Discovered share: %s\n",shares[i]); } run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{ // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{ run('select ' + shar); printf(" SHARE: %s\n", shar); try { run('users'); printf(" %20s %11s %11s %3s\n","Username","Usage(G)","Quota(G)","Quota(%)"); printf(" %20s %11s %11s %4s\n","--------","--------","--------","----"); users=list(); for(k=0; k < users.length; k++) { user=users[k]; getUserQuota(user); } run('done'); // exit user context } catch(err) { printf(" SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar); } run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec 6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME MODIFIED TYPE COMMENT key-000 2010-10-25 20:56:42 RSA cycloneRSAKey key-001 2010-12-6 17:44:53 RSA LightningRSAKey As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley ** 25 October 2010 **************************************/function getUserQuota(usr){ run('select ' + usr); var username=get('name'); var usage=get('usage'); var quota=get('quota'); var usage_g=usage / 1073741824; // convert bytes to gigabytes var quota_g=quota / 1073741824; // as above var quota_percent=0 if (quota > 0) { quota_percent=(usage / quota)*(100/1); } printf(" %20s %8.2f %8.2f %d%%\n",username,usage_g,quota_g,quota_percent); run('done'); // done with this selected user}function getShareQuota(shar){ //printf("DEBUG: selecting share %s\n", shar); run('select ' + shar); printf(" SHARE: %s\n", shar); try { run('users'); printf(" %20s %11s %11s %3s\n","Username","Usage(G)","Quota(G)","Quota(%)"); printf(" %20s %11s %11s %4s\n","--------","--------","--------","--------"); users=list(); for(k=0; k < users.length; k++) { user=users[k]; getUserQuota(user); } run('done'); // exit user context } catch(err) { printf(" SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar); } run('done'); // done with this share}function getShares(proj){ //printf("DEBUG: selecting project %s\n",proj); run('select ' + proj); shares=list(); printf("Project: %s\n", proj); for(j=0; j < shares.length; j++) { share=shares[j]; getShareQuota(share); } run('done'); // exit selected project}function getProjects(){ run('cd /'); run('shares'); projects=list(); for (i=0; i < projects.length; i++) { var project=projects[i]; getShares(project); } run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project SHARE: and-another Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- nobody 0.00 0.00 0% geoffro 0.05 0.00 0% Billy 0.10 0.00 0% root 0.00 0.00 0% testing-user 0.05 0.00 0% SHARE: another-share Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- root 0.00 0.00 0% nobody 0.00 0.00 0% geoffro 0.05 0.49 9% testing-user 0.05 0.02 249% Billy 0.10 0.29 33% SHARE: bob Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- nobody 0.00 0.00 0% root 0.00 0.00 0% SHARE: more-shares-for-all Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- Billy 0.10 0.00 0% testing-user 0.05 0.00 0% nobody 0.00 0.00 0% root 0.00 0.00 0% geoffro 0.05 0.00 0% SHARE: yep Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- root 0.00 0.00 0% nobody 0.00 0.00 0% Billy 0.10 0.01 999% testing-user 0.05 0.49 9% geoffro 0.05 0.00 0%Project: default SHARE: Test-LUN SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users SHARE: test-geoff Username Usage(G) Quota(G) Quota(%) -------- -------- -------- -------- geoffro 0.05 0.00 0% root 3.18 10.00 31% uucp 0.00 0.00 0% nobody 0.59 0.49 119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide): ...parameters: variableParam1: { label: 'Name of Share', type: 'String' }, variableParam2 { label: 'Share Size', type: 'size' },execute: ....}; Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () { run('cd /'); run('shares'); projects=list(); for (i=0; i < projects.length; i++) { run('select ' + projects[i]); shares=list('filesystem'); printf("Project: %s\n", projects[i]); for(j=0; j < shares.length; j++) { run('select ' +shares[j]); try { run('users'); printf(" SHARE: %s\n", shares[j]); printf(" %20s %11s %11s %3s\n","Username","Usage(G)","Quota(G)","Quota(%)"); printf(" %20s %11s %11s %4s\n","--------","--------","--------","-------"); users=list(); for(k=0; k < users.length; k++) { run('select ' + users[k]); username=get('name'); usage=get('usage'); quota=get('quota'); usage_g=usage / 1073741824; // convert bytes to gigabytes quota_g=quota / 1073741824; // as above quota_percent=0 if (quota > 0) { quota_percent=(usage / quota)*(100/1); } printf(" %20s %8.2f %8.2f %d%%\n",username,usage_g,quota_g,quota_percent); run('done'); } run('done'); // exit user context } catch(err) { // printf(" %s is a LUN, Not looking for users\n", shares[j]); } run('done'); // exit selected share context } run('done'); // exit project context } }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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Char error C langauge

- by Nadeem tabbaa

i have a project for a course, i did almost everything but i have this error i dont know who to solve it... the project about doing our own shell some of them we have to write our code, others we will use the fork method.. this is the code, #include <sys/wait.h> #include <dirent.h> #include <limits.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include<stdio.h> #include<fcntl.h> #include<unistd.h> #include<sys/stat.h> #include<sys/types.h> int main(int argc, char **argv) { pid_t pid; char str[21], *arg[10]; int x,status,number; system("clear"); while(1) { printf("Rshell>" ); fgets(str,21,stdin); x = 0; arg[x] = strtok(str, " \n\t"); while(arg[x]) arg[++x] = strtok(NULL, " \n\t"); if(NULL!=arg[0]) { if(strcasecmp(arg[0],"cat")==0) //done { int f=0,n; char l[1]; struct stat s; if(x!=2) { printf("Mismatch argument\n"); } /*if(access(arg[1],F_OK)) { printf("File Exist"); exit(1); } if(stat(arg[1],&s)<0) { printf("Stat ERROR"); exit(1); } if(S_ISREG(s.st_mode)<0) { printf("Not a Regular FILE"); exit(1); } if(geteuid()==s.st_uid) if(s.st_mode & S_IRUSR) f=1; else if(getegid()==s.st_gid) if(s.st_mode & S_IRGRP) f=1; else if(s.st_mode & S_IROTH) f=1; if(!f) { printf("Permission denied"); exit(1); }*/ f=open(arg[1],O_RDONLY); while((n=read(f,l,1))>0) write(1,l,n); } else if(strcasecmp(arg[0],"rm")==0) //done { if( unlink( arg[1] ) != 0 ) perror( "Error deleting file" ); else puts( "File successfully deleted" ); } else if(strcasecmp(arg[0],"rmdir")==0) //done { if( remove( arg[1] ) != 0 ) perror( "Error deleting Directory" ); else puts( "Directory successfully deleted" ); } else if(strcasecmp(arg[0],"ls")==0) //done { DIR *dir; struct dirent *dirent; char *where = NULL; //printf("x== %i\n",x); //printf("x== %s\n",arg[1]); //printf("x== %i\n",get_current_dir_name()); if (x == 1) where = get_current_dir_name(); else where = arg[1]; if (NULL == (dir = opendir(where))) { fprintf(stderr,"%d (%s) opendir %s failed\n", errno, strerror(errno), where); return 2; } while (NULL != (dirent = readdir(dir))) { printf("%s\n", dirent->d_name); } closedir(dir); } else if(strcasecmp(arg[0],"cp")==0) //not yet for Raed { FILE *from, *to; char ch; if(argc!=3) { printf("Usage: copy <source> <destination>\n"); exit(1); } /* open source file */ if((from = fopen(argv[1], "rb"))==NULL) { printf("Cannot open source file.\n"); exit(1); } /* open destination file */ if((to = fopen(argv[2], "wb"))==NULL) { printf("Cannot open destination file.\n"); exit(1); } /* copy the file */ while(!feof(from)) { ch = fgetc(from); if(ferror(from)) { printf("Error reading source file.\n"); exit(1); } if(!feof(from)) fputc(ch, to); if(ferror(to)) { printf("Error writing destination file.\n"); exit(1); } } if(fclose(from)==EOF) { printf("Error closing source file.\n"); exit(1); } if(fclose(to)==EOF) { printf("Error closing destination file.\n"); exit(1); } } else if(strcasecmp(arg[0],"mv")==0)//done { if( rename(arg[1],arg[2]) != 0 ) perror( "Error moving file" ); else puts( "File successfully moved" ); } else if(strcasecmp(arg[0],"hi")==0)//done { printf("hello\n"); } else if(strcasecmp(arg[0],"exit")==0) // done { return 0; } else if(strcasecmp(arg[0],"sleep")==0) // done { if(x==1) printf("plz enter the # seconds to sleep\n"); else sleep(atoi(arg[1])); } else if(strcmp(arg[0],"history")==0) // not done { FILE *infile; //char fname[40]; char line[100]; int lcount; ///* Read in the filename */ //printf("Enter the name of a ascii file: "); //fgets(History.txt, sizeof(fname), stdin); /* Open the file. If NULL is returned there was an error */ if((infile = fopen("History.txt", "r")) == NULL) { printf("Error Opening File.\n"); exit(1); } while( fgets(line, sizeof(line), infile) != NULL ) { /* Get each line from the infile */ lcount++; /* print the line number and data */ printf("Line %d: %s", lcount, line); } fclose(infile); /* Close the file */ writeHistory(arg); //write to txt file every new executed command //read from the file once the history command been called //if a command called not for the first time then just replace it to the end of the file } else if(strncmp(arg[0],"@",1)==0) // not done { //scripting files // read from the file command by command and executing them } else if(strcmp(arg[0],"type")==0) //not done { //if(x==1) //printf("plz enter the argument\n"); //else //type((arg[1])); } else { pid = fork( ); if (pid == 0) { execlp(arg[0], arg[0], arg[1], arg[2], NULL); printf ("EXEC Failed\n"); } else { wait(&status); if(strcmp(arg[0],"clear")!=0) { printf("status %04X\n",status); if(WIFEXITED(status)) printf("Normal termination, exit code %d\n", WEXITSTATUS(status)); else printf("Abnormal termination\n"); } } } } } } void writeHistory(char *arg[]) { FILE *file; file = fopen("History.txt","a+"); /* apend file (add text to a file or create a file if it does not exist.*/ int i =0; while(strcasecmp(arg[0],NULL)==0) { fprintf(file,"%s ",arg[i]); /*writes*/ } fprintf(file,"\n"); /*new line*/ fclose(file); /*done!*/ getchar(); /* pause and wait for key */ //return 0; } the thing is when i compile the code, this what it gives me /home/ugics/st255375/ICS431Labs/Project/Rshell.c: At top level: /home/ugics/st255375/ICS431Labs/Project/Rshell.c:264: warning: conflicting types for ‘writeHistory’ /home/ugics/st255375/ICS431Labs/Project/Rshell.c:217: note: previous implicit declaration of ‘writeHistory’ was here can any one help me??? thanks

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How to use sprintf instead of hardcoded values

- by astha goyal

I am developing a firewall for Linux as my project. I am able to capture packets and to block them. I am using IPTABLES. How can I use variables with sprintf instead of hardcoded values? sprintf(comm, "iptables -A INPUT -s $str -j DROP") // inplace of: sprintf(comm, "iptables -A INPUT -s 192.168.0.43 -j DROP")

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snprintf vs strcpy(etc) in c

- by monkeyking

For doing string concatenation I've been doing basic strcpy,strncpy of char* buffers. Then I learned about the snprintf and friends. Should I stick with my strcpy,strcpy + \0 terminiation. Or should I just use snprintf in the future? thanks

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PHP - print content from file after manipulation

- by ludicco

Hello there, I'm struggling trying to read a php file inside a php and do some manipulation..after that have the content as a string, but when I try to output that with echo or print all the php tags are literally included on the file. so here is my code: function compilePage($page,$path){ $contents = array(); $menu = getMenuFor($page); $file = file_get_contents($path); array_push($contents,$menu); array_push($contents,$file); return implode("\n",$contents); } and this will return a string like <div id="content> <h2>Here is my title</h2> <p><? echo "my body text"; ?></p> </div> but this will print exactly the content above not compiling the php on it. So, how can I render this "compilePage" making sure it returns a compiled php result and not just a plain text? Thanks in advance

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Java Formatter specify starting position for text

- by purecharger

I'm trying to position a string at a certain starting position on a line, regardless of where the previous text ended. For instance: Mandatory arguments to long options are mandatory for short options too. -a, --all do not ignore entries starting with . -A, --almost-all do not list implied . and .. The explanation of the options begin at position 30 regardless of the text preceding. How do you accomplish this with java.util.Formatter? I have tested with both the width (%30s) and precision (%.30) arguments, and neither provide the desired result.

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Whats the easiest way to convert a long in C to a char*?

- by dh82

What is the clean way to do that in C? wchar_t* ltostr(long value) { int size = string_size_of_long(value); wchar_t *wchar_copy = malloc(value * sizeof(wchar_t)); swprintf(wchar_copy, size, L"%li", self); return wchar_copy; } The solutions I came up so far are all rather ugly, especially allocate_properly_size_whar_t uses double float base math.

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Unwanted character being added to string in C

- by Church

I have a program that gives you shipping addresses from an input file. However at the beginning of one of the strings, order.add_one, a number is being added to the beginning of the string, that number is equivalent to the variable "choice" every time. Why is it doing this? #include <stdio.h> #include <math.h> #include <string.h> //structure typedef struct {char cust_name[25]; char cust_id[3]; char add_one[30]; char add_two[30]; char bike; char risky; int number_ordered; char cust_information[500]; }ORDER; ORDER order; int main(void){ fflush(stdin); system ( "clear" ); //initialize variables float price; float m = 359.95; float s = 279.95; //while loop, runs until user declares they no longer wish to input orders while (1==1){ printf("Options: \nEnter Customer information manually : 1 \nSearch Customer by ID(input.txt reader) : 2 \n"); int option = 0; scanf(" %d", &option); if (option == 1){ //Print and scan statements printf("Enter Customer Information\n"); printf("Customer Name: "); scanf(" %[^\n]s", &order.cust_name); printf("\nEnter Address Line One: "); scanf(" %[^\n]s", &order.add_one); printf("\nEnter Addres Line Two: "); scanf(" %[^\n]s", &order.add_two); printf("\nHow Many Bicycles Are Ordered: "); scanf(" %d", &order.number_ordered); printf("\nWhat Type Of Bike Is Ordered\n M Mountain Bike \n S Street Bike"); printf("\nChoose One (M or S): "); scanf(" %c", &order.bike); printf("\nIs The Customer Risky (Y/N): "); scanf(" %c", &order.risky); system ( "clear" ); } if (option == 2){ FILE *fpt; fpt = fopen("input.txt", "r"); if (fpt==NULL){ printf("Text file did not open\n"); return 1; } printf("Enter Customer ID: "); scanf("%s", &order.cust_id); char choice; choice = order.cust_id[0]; char x[3]; int w, u, y, z; char a[10], b[10], c[10], d[10], e[20], f[10], g[10], i[1], j[1]; int h; printf("%s value of c", c); if (choice >='1'){ while ((w = fgetc(fpt)) != '\n' ){ } } if (choice >='2'){ while ((u = fgetc(fpt)) != '\n' ){ } } if (choice >='3'){ while ((y = fgetc(fpt)) != '\n' ){ } } if (choice >= '4'){ while ((z = fgetc(fpt)) != '\n' ){ } } printf("\n"); fscanf(fpt, "%s", x); fscanf(fpt, "%s", a); printf("%s", a); strcat(order.cust_name, a); fscanf(fpt, " %s", b); printf(" %s", b); strcat(order.cust_name, " "); strcat(order.cust_name, b); fscanf(fpt, "%s", c); printf(" %s", c); strcat(order.add_one, "\0"); strcat(order.add_one, c); fscanf(fpt, "%s", d); printf(" %s", d); strcat(order.add_one, " "); strcat(order.add_one, d); fscanf(fpt, "%s", e); printf(" %s", e); strcat(order.add_two, e); fscanf(fpt, "%s", f); printf(" %s", f); strcat(order.add_two, " "); strcat(order.add_two, f); fscanf(fpt, "%s", g); printf(" %s", g); strcat(order.add_two, " "); strcat(order.add_two, g); strcat(order.add_two, "\0"); fscanf(fpt, "%d", &h); printf(" %d", h); order.number_ordered = h; fscanf(fpt, "%s", i); printf(" %s", i); order.bike = i[0]; fscanf(fpt, "%s", j); printf(" %s", j); order.risky = j[0]; fclose(fpt); printf("%s %s %s %d %c %c", order.cust_name, order.add_one, order.add_two, order.number_ordered, order.bike, order.risky); }

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how to print numbers using for loop in java?

- by Balkrushn Viroja

I have one text box in which I take the value of how many number do you want to print. Now My question is that how can I use for loop so that the number which I want to print is equal to the number that I got from textbox.One more thing is that i want to print only three numbers in one line. i.e. If I got 14 in my text box the result will look like below. 1 2 3 4 5 6 7 8 9 10 11 12 13 14

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Processing incorrect mac addresses from 802.11 frames with pcap

- by Quentin Swain

I'm working throurgh a project with pcap and wireless. Following an example posted in response to oe of my earlier questions I am trying to extract the mac addresses from wireless frames. I have created structures for the radiotap header and a basic management frame. For some reason when it comes to trying to output the mac addresses I am printing out the wrong data. When I compare to wireshark I don't see why the radio tap data is printing out correctly but the mac addresses are not. I don't see any additional padding in the hex dump that wireshark displays when i look at the packets and compare the packets that I have captured. I am somewhat famialar with c but not an expert so maybe I am not using the pointers and structures properly could someone help show me what I am doing wrong? Thanks, Quentin // main.c // MacSniffer // #include <pcap.h> #include <string.h> #include <stdlib.h> #define MAXBYTES2CAPTURE 65535 #ifdef WORDS_BIGENDIAN typedef struct frame_control { unsigned int subtype:4; /*frame subtype field*/ unsigned int protoVer:2; /*frame type field*/ unsigned int version:2; /*protocol version*/ unsigned int order:1; unsigned int protected:1; unsigned int moreDate:1; unsigned int power_management:1; unsigned int retry:1; unsigned int moreFrag:1; unsigned int fromDS:1; unsigned int toDS:1; }frame_control; struct ieee80211_radiotap_header{ u_int8_t it_version; u_int8_t it_pad; u_int16_t it_len; u_int32_t it_present; u_int64_t MAC_timestamp; u_int8_t flags; u_int8_t dataRate; u_int16_t channelfrequency; u_int16_t channFreq_pad; u_int16_t channelType; u_int16_t channType_pad; u_int8_t ssiSignal; u_int8_t ssiNoise; u_int8_t antenna; }; #else typedef struct frame_control { unsigned int protoVer:2; /* protocol version*/ unsigned int type:2; /*frame type field (Management,Control,Data)*/ unsigned int subtype:4; /* frame subtype*/ unsigned int toDS:1; /* frame coming from Distribution system */ unsigned int fromDS:1; /*frame coming from Distribution system */ unsigned int moreFrag:1; /* More fragments?*/ unsigned int retry:1; /*was this frame retransmitted*/ unsigned int powMgt:1; /*Power Management*/ unsigned int moreDate:1; /*More Date*/ unsigned int protectedData:1; /*Protected Data*/ unsigned int order:1; /*Order*/ }frame_control; struct ieee80211_radiotap_header{ u_int8_t it_version; u_int8_t it_pad; u_int16_t it_len; u_int32_t it_present; u_int64_t MAC_timestamp; u_int8_t flags; u_int8_t dataRate; u_int16_t channelfrequency; u_int16_t channelType; int ssiSignal:8; int ssiNoise:8; }; #endif struct wi_frame { u_int16_t fc; u_int16_t wi_duration; u_int8_t wi_add1[6]; u_int8_t wi_add2[6]; u_int8_t wi_add3[6]; u_int16_t wi_sequenceControl; // u_int8_t wi_add4[6]; //unsigned int qosControl:2; //unsigned int frameBody[23124]; }; void processPacket(u_char *arg, const struct pcap_pkthdr* pkthdr, const u_char* packet) { int i= 0, *counter = (int *) arg; struct ieee80211_radiotap_header *rh =(struct ieee80211_radiotap_header *)packet; struct wi_frame *fr= (struct wi_frame *)(packet + rh->it_len); u_char *ptr; //printf("Frame Type: %d",fr->wi_fC->type); printf("Packet count: %d\n", ++(*counter)); printf("Received Packet Size: %d\n", pkthdr->len); if(rh->it_version != NULL) { printf("Radiotap Version: %d\n",rh->it_version); } if(rh->it_pad!=NULL) { printf("Radiotap Pad: %d\n",rh->it_pad); } if(rh->it_len != NULL) { printf("Radiotap Length: %d\n",rh->it_len); } if(rh->it_present != NULL) { printf("Radiotap Present: %c\n",rh->it_present); } if(rh->MAC_timestamp != NULL) { printf("Radiotap Timestamp: %u\n",rh->MAC_timestamp); } if(rh->dataRate != NULL) { printf("Radiotap Data Rate: %u\n",rh->dataRate); } if(rh->channelfrequency != NULL) { printf("Radiotap Channel Freq: %u\n",rh->channelfrequency); } if(rh->channelType != NULL) { printf("Radiotap Channel Type: %06x\n",rh->channelType); } if(rh->ssiSignal != NULL) { printf("Radiotap SSI signal: %d\n",rh->ssiSignal); } if(rh->ssiNoise != NULL) { printf("Radiotap SSI Noise: %d\n",rh->ssiNoise); } ptr = fr->wi_add1; int k= 6; printf("Destination Address:"); do{ printf("%s%X",(k==6)?" ":":",*ptr++); } while(--k>0); printf("\n"); ptr = fr->wi_add2; k=0; printf("Source Address:"); do{ printf("%s%X",(k==6)?" ":":",*ptr++); }while(--k>0); printf("\n"); ptr = fr->wi_add3; k=0; do{ printf("%s%X",(k==6)?" ":":",*ptr++); } while(--k>0); printf("\n"); /* for(int j = 0; j < 23124;j++) { if(fr->frameBody[j]!= NULL) { printf("%x",fr->frameBody[j]); } } */ for (i = 0;i<pkthdr->len;i++) { if(isprint(packet[i +rh->it_len])) { printf("%c",packet[i + rh->it_len]); } else{printf(".");} //print newline after each section of the packet if((i%16 ==0 && i!=0) ||(i==pkthdr->len-1)) { printf("\n"); } } return; } int main(int argc, char** argv) { int count = 0; pcap_t* descr = NULL; char errbuf[PCAP_ERRBUF_SIZE], *device = NULL; struct bpf_program fp; char filter[]="wlan broadcast"; const u_char* packet; memset(errbuf,0,PCAP_ERRBUF_SIZE); device = argv[1]; if(device == NULL) { fprintf(stdout,"Supply a device name "); } descr = pcap_create(device,errbuf); pcap_set_rfmon(descr,1); pcap_set_promisc(descr,1); pcap_set_snaplen(descr,30); pcap_set_timeout(descr,10000); pcap_activate(descr); int dl =pcap_datalink(descr); printf("The Data Link type is %s",pcap_datalink_val_to_name(dl)); //pcap_dispatch(descr,MAXBYTES2CAPTURE,1,512,errbuf); //Open device in promiscuous mode //descr = pcap_open_live(device,MAXBYTES2CAPTURE,1,512,errbuf); /* if(pcap_compile(descr,&fp,filter,0,PCAP_NETMASK_UNKNOWN)==-1) { fprintf(stderr,"Error compiling filter\n"); exit(1); } if(pcap_setfilter(descr,&fp)==-1) { fprintf(stderr,"Error setting filter\n"); exit(1); } */ pcap_loop(descr,0, processPacket, (u_char *) &count); return 0; }

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segmentation fault using scanf

- by agarrow

noob question here: I'm trying to write a simple menu interface, but I keep getting a segmentation fault error and I can't figure out why. #include <stdlib.h> #include <stdio.h> int flush(); int add(char *name, char *password, char *type); int delete(char *name); int edit(char *name, char *password, char *type, char *newName, char *newPassword, char *newType); int verify(char *name, char *password); int menu(){ int input; char *name, *password, *type, *newName, *newPassword, *newType; printf("MAIN MENU \n ============\n"); printf("1. ADD\n"); printf("2. DELETE\n"); printf("3. EDIT\n"); printf("4. VERIFY\n"); printf("5. Exit\n"); printf("Selection:"); scanf("%d", &input); flush(); switch (input){ case 1: printf("%s\n", "Enter Name:"); scanf("%s", name); flush(); printf("%s\n", "enter password" ); scanf("%s", password); flush(); printf("%s\n","enter type" ); scanf("%s",type); add(name, password, type); menu(); break; case 2: printf("Enter Name:" ); scanf("%s",name); flush(); delete(name); menu(); break; case 3: printf("Enter Name:\n"); scanf("%s",name); flush(); printf("Enter Password\n"); scanf("%s", password); flush(); printf("enter type:\n"); scanf("%s", type); flush(); printf("enter your new username:\n"); scanf("%s",newName); flush(); printf("enter your new password\n"); scanf("%s", newPassword); flush(); printf("enter your new type\n"); scanf("%s",newType); flush(); edit(name, password, type, newName, newPassword, newType); menu(); break; case 4: printf("Enter Name\n"); scanf("%s",name); flush(); printf("Enter Password\n"); scanf("%s",password); flush(); verify(name, password); menu(); break; case 5: return 0; default: printf("invalid input, please select from the following:\n"); menu(); } return 0; } int flush(){ int ch; while ((ch = getchar()) != EOF && ch != '\n') ; return 0; } I get the segmentation fault after entering two fields, in any menu option

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How to printf a time_t variable as a floating point number?

- by soneangel

Hi guys, I'm using a time_t variable in C (openMP enviroment) to keep cpu execution time...I define a float value sum_tot_time to sum time for all cpu's...I mean sum_tot_time is the sum of cpu's time_t values. The problem is that printing the value sum_tot_time it appear as an integer or long, by the way without its decimal part! I tried in these ways: to printf sum_tot_time as a double being a double value to printf sum_tot_time as float being a float value to printf sum_tot_time as double being a time_t value to printf sum_tot_time as float being a time_t value Please help me!!

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Link List Problem,

- by david

OK i have a problem with a Link List program i'm trying to Do, the link List is working fine. Here is my code #include <iostream> using namespace std; struct record { string word; struct record * link; }; typedef struct record node; node * insert_Node( node * head, node * previous, string key ); node * search( node *head, string key, int *found); void displayList(node *head); node * delete_node( node *head, node * previous, string key); int main() { node * previous, * head = NULL; int found = 0; string node1Data,newNodeData, nextData,lastData; //set up first node cout <<"Depature"<<endl; cin >>node1Data; previous = search( head, node1Data, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, node1Data); cout <<"Depature inserted"<<endl; //insert node between first node and head cout <<"Destination"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Destinationinserted"<<endl; //insert node between second node and head cout <<"Cost"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Cost inserted"<<endl; cout <<"Number of Seats Required"<<endl; //place node between new node and first node cin >>nextData; previous = search( head, nextData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, nextData); cout <<"Number of Seats Required inserted"<<endl; //insert node between first node and head cout <<"Name"<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Name inserted"<<endl; //insert node between node and head cout <<"Address "<<endl; cin >>newNodeData; previous = search( head, newNodeData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, newNodeData); cout <<"Address inserted"<<endl; //place node as very last node cin >>lastData; previous = search( head, lastData, &found); cout <<"Previous" <<previous<<endl; head = insert_Node(head, previous, lastData); cout <<"C"<<endl; displayList(head); char Ans = 'y'; //Delete nodes do { cout <<"Enter Keyword to be delete"<<endl; cin >>nextData; previous = search( head, nextData, &found); if (found == 1) head = delete_node( head, previous,nextData); displayList(head); cout <<"Do you want to Delete more y /n "<<endl; cin >> Ans; } while( Ans =='y'); int choice, i=0, counter=0; int fclass[10]; int coach[10]; printf("Welcome to the booking program"); printf("\n-----------------"); do{ printf("\n Please pick one of the following option:"); printf("\n 1) Reserve a first class seat on Flight 101."); printf("\n 2) Reserve a coach seat on Flight 101."); printf("\n 3) Quit "); printf("\n ---------------------------------------------------------------------"); printf("\nYour choice?"); scanf("%d",&choice); switch(choice) { case 1: i++; if (i <10){ printf("Here is your seat: %d " , fclass[i]); } else if (i = 10) { printf("Sorry there is no more seats on First Class. Please wait for the next flight"); } break; case 2: if (i <10){ printf("Here is your Seat Coach: %d " , coach[i]); } else if ( i = 10) { printf("Sorry their is no more Seats on Coach. Please wait for the next flight"); } break; case 3: printf("Thank you and goodbye\n"); //exit(0); } } while (choice != 3); } /******************************************************* search function to return previous position of node ******************************************************/ node * search( node *head, string key, int *found) { node * previous, * current; current = head; previous = current; *found = 0;//not found //if (current->word < key) move through links until the next link //matches or current_word > key while( current !=NULL) { //compare exactly if (key ==current->word ) { *found = 1; break; } //if key is less than word else if ( key < current->word ) break; else { //previous stays one link behind current previous = current; current = previous -> link; } } return previous; } /******************************************************** display function as used with createList ******************************************************/ void displayList(node *head) { node * current; //current now contains the address held of the 1st node similar //to head current = head; cout << "\n\n"; if( current ==NULL) cout << "Empty List\n\n"; else { /*Keep going displaying the contents of the list and set current to the address of the next node. When set to null, there are no more nodes */ while(current !=NULL) { cout << current->word<<endl; current = current ->link; } } } /************************************************************ insert node used to position node (i) empty list head = NULL (ii) to position node before the first node key < head->word (iii) every other position including the end of the list This is done using the following steps (a) Pass in all the details to create the node either details or a whole record (b) Pass the details over to fill the node (C) Use the if statement to add the node to the list **********************************************************/ node * insert_Node( node * head, node * previous, string key ) { node * new_node, * temp; new_node = new node; //create the node new_node ->word = key; new_node -> link = NULL; if (head == NULL || key < head->word ) //empty list { //give address of head to temp temp = head; //head now points to the new_node head = new_node; //new_node now points to what head was pointing at new_node -> link = temp; } else { //pass address held in link to temp temp = previous-> link; //put address of new node to link of previous previous -> link = new_node; //pass address of temp to link of new node new_node -> link = temp; } return head; } node * delete_node( node *head, node * previous, string key) { /* this function will delete a node but will not return its contents */ node * temp; if(key == head->word) //delete node at head of list { temp = head; //point head at the next node head = head -> link; } else { //holds the address of the node after the one // to be deleted temp = previous-> link; /*assign the previous to the address of the present node to be deleted which holds the address of the next node */ previous-> link = previous-> link-> link; } delete temp; return head; }//end delete The problem i have is when i Enter in the Number 2 in the Node(Seats) i like to get a Counter Taken 2 off of 50, some thing like what i have here enter code here int choice, i=0, counter=0; int fclass[10]; int coach[10]; printf("Welcome to the booking program"); printf("\n-----------------"); do{ printf("\n Please pick one of the following option:"); printf("\n 1) Reserve a first class seat on Flight 101."); printf("\n 2) Reserve a coach seat on Flight 101."); printf("\n 3) Quit "); printf("\n ---------------------------------------------------------------------"); printf("\nYour choice?"); scanf("%d",&choice); switch(choice) { case 1: i++; if (i <10){ printf("Here is your seat: %d " , fclass[i]); } else if (i = 10) { printf("Sorry there is no more seats on First Class. Please wait for the next flight"); } break; case 2: if (i <10){ printf("Here is your Seat Coach: %d " , coach[i]); } else if ( i = 10) { printf("Sorry their is no more Seats on Coach. Please wait for the next flight"); } break; case 3: printf("Thank you and goodbye\n"); //exit(0); } } while (choice != 3); How can i get what the User enters into number of Seats into this function

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An error saying unidentifed function "push", "pop", and"display" occurs, what should i add to fix i

- by Alesha Aris

#include<stdio.h> #include<iostream.h> #include<conio.h> #include<stdlib.h>(TOP) #include<fstream.h> #define MAX 5 int top = -1; int stack_arr[MAX]; main() { int choice; while(1) { printf("1.Push\n"); printf("2.Pop\n"); printf("3.Display\n"); printf("4.Quit\n"); printf("Enter your choice : "); scanf("%d",&choice); switch(choice) { case 1 : push(); break; case 2: pop(); break; case 3: display(); break; case 4: exit(1); default: printf("Wrong choice\n"); }/*End of switch*/ }/*End of while*/ }/*End of main()*/ push() { int pushed_item; if(top == (MAX-1)) printf("Stack Overflow\n"); else { printf("Enter the item to be pushed in stack : "); scanf("%d",&pushed_item); top=top+1; stack_arr[top] = pushed_item; } }/*End of push()*/ pop() { if(top == -1) printf("Stack Underflow\n"); else { printf("Popped element is : %d\n",stack_arr[top]); top=top-1; } }/*End of pop()*/ display() { int i; if(top == -1) printf("Stack is empty\n"); else { printf("Stack elements :\n"); for(i = top; i >=0; i--) printf("%d\n", stack_arr[i] ); } }/*End of display()*/

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socket operation on nonsocket or bad file descriptor

- by Magn3s1um

I'm writing a pthread server which takes requests from clients and sends them back a bunch of .ppm files. Everything seems to go well, but sometimes when I have just 1 client connected, when trying to read from the file descriptor (for the file), it says Bad file Descriptor. This doesn't make sense, since my int fd isn't -1, and the file most certainly exists. Other times, I get this "Socket operation on nonsocket" error. This is weird because other times, it doesn't give me this error and everything works fine. When trying to connect multiple clients, for some reason, it will only send correctly to one, and then the other client gets the bad file descriptor or "nonsocket" error, even though both threads are processing the same messages and do the same routines. Anyone have an idea why? Here's the code that is giving me that error: while(mqueue.head != mqueue.tail && count < dis_m){ printf("Sending to client %s: %s\n", pointer->id, pointer->message); int fd; fd = open(pointer->message, O_RDONLY); char buf[58368]; int bytesRead; printf("This is fd %d\n", fd); bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); fflush(stdout); close(fd); mqueue.mcount--; mqueue.head = mqueue.head->next; free(pointer->message); free(pointer); pointer = mqueue.head; count++; } printf("Sending %s\n", pointer->message); int fd; fd = open(pointer->message, O_RDONLY); printf("This is fd %d\n", fd); printf("I am hhere2\n"); char buf[58368]; int bytesRead; bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); close(fd); mqueue.mcount--; if(mqueue.head != mqueue.tail){ mqueue.head = mqueue.head->next; } else{ mqueue.head->next = malloc(sizeof(struct message)); mqueue.head = mqueue.head->next; mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.head->message = NULL; } free(pointer->message); free(pointer); pthread_mutex_unlock(&numm); pthread_mutex_unlock(&circ); pthread_mutex_unlock(&slots); The messages for both threads are the same, being of the form ./path/imageXX.ppm where XX is the number that should go to the client. The file size of each image is 58368 bytes. Sometimes, this code hangs on the read, and stops execution. I don't know this would be either, because the file descriptor comes back as valid. Thanks in advanced. Edit: Here's some sample output: Sending to client a: ./support/images/sw90.ppm This is fd 4 Error: : Socket operation on non-socket Sending to client a: ./support/images/sw91.ppm This is fd 4 Error: : Socket operation on non-socket Sending ./support/images/sw92.ppm This is fd 4 I am hhere2 Error: : Socket operation on non-socket My dispatcher has defeated evil Sample with 2 clients (client b was serviced first) Sending to client b: ./support/images/sw87.ppm This is fd 6 Error: : Success Sending to client b: ./support/images/sw88.ppm This is fd 6 Error: : Success Sending to client b: ./support/images/sw89.ppm This is fd 6 Error: : Success This is fd 6 Error: : Bad file descriptor Sending to client a: ./support/images/sw85.ppm This is fd 6 Error: As you can see, who ever is serviced first in this instance can open the files, but not the 2nd person. Edit2: Full code. Sorry, its pretty long and terribly formatted. #include <netinet/in.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/inet.h> #include <sys/types.h> #include <sys/socket.h> #include <errno.h> #include <stdio.h> #include <unistd.h> #include <pthread.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include "ring.h" /* Version 1 Here is what is implemented so far: The threads are created from the arguments specified (number of threads that is) The server will lock and update variables based on how many clients are in the system and such. The socket that is opened when a new client connects, must be passed to the threads. To do this, we need some sort of global array. I did this by specifying an int client and main_pool_busy, and two pointers poolsockets and nonpoolsockets. My thinking on this was that when a new client enters the system, the server thread increments the variable client. When a thread is finished with this client (after it sends it the data), the thread will decrement client and close the socket. HTTP servers act this way sometimes (they terminate the socket as soon as one transmission is sent). *Note down at bottom After the server portion increments the client counter, we must open up a new socket (denoted by new_sd) and get this value to the appropriate thread. To do this, I created global array poolsockets, which will hold all the socket descriptors for our pooled threads. The server portion gets the new socket descriptor, and places the value in the first spot of the array that has a 0. We only place a value in this array IF: 1. The variable main_pool_busy < worknum (If we have more clients in the system than in our pool, it doesn't mean we should always create a new thread. At the end of this, the server signals on the condition variable clientin that a new client has arrived. In our pooled thread, we then must walk this array and check the array until we hit our first non-zero value. This is the socket we will give to that thread. The thread then changes the array to have a zero here. What if our all threads in our pool our busy? If this is the case, then we will know it because our threads in this pool will increment main_pool_busy by one when they are working on a request and decrement it when they are done. If main_pool_busy >= worknum, then we must dynamically create a new thread. Then, we must realloc the size of our nonpoolsockets array by 1 int. We then add the new socket descriptor to our pool. Here's what we need to figure out: NOTE* Each worker should generate 100 messages which specify the worker thread ID, client socket descriptor and a copy of the client message. Additionally, each message should include a message number, starting from 0 and incrementing for each subsequent message sent to the same client. I don't know how to keep track of how many messages were to the same client. Maybe we shouldn't close the socket descriptor, but rather keep an array of structs for each socket that includes how many messages they have been sent. Then, the server adds the struct, the threads remove it, then the threads add it back once they've serviced one request (unless the count is 100). ------------------------------------------------------------- CHANGES Version 1 ---------- NONE: this is the first version. */ #define MAXSLOTS 30 #define dis_m 15 //problems with dis_m ==1 //Function prototypes void inc_clients(); void init_mutex_stuff(pthread_t*, pthread_t*); void *threadpool(void *); void server(int); void add_to_socket_pool(int); void inc_busy(); void dec_busy(); void *dispatcher(); void create_message(long, int, int, char *, char *); void init_ring(); void add_to_ring(char *, char *, int, int, int); int socket_from_string(char *); void add_to_head(char *); void add_to_tail(char *); struct message * reorder(struct message *, struct message *, int); int get_threadid(char *); void delete_socket_messages(int); struct message * merge(struct message *, struct message *, int); int get_request(char *, char *, char*); ///////////////////// //Global mutexes and condition variables pthread_mutex_t startservice; pthread_mutex_t numclients; pthread_mutex_t pool_sockets; pthread_mutex_t nonpool_sockets; pthread_mutex_t m_pool_busy; pthread_mutex_t slots; pthread_mutex_t numm; pthread_mutex_t circ; pthread_cond_t clientin; pthread_cond_t m; /////////////////////////////////////// //Global variables int clients; int main_pool_busy; int * poolsockets, nonpoolsockets; int worknum; struct ring mqueue; /////////////////////////////////////// int main(int argc, char ** argv){ //error handling if not enough arguments to program if(argc != 3){ printf("Not enough arguments to server: ./server portnum NumThreadsinPool\n"); _exit(-1); } //Convert arguments from strings to integer values int port = atoi(argv[1]); worknum = atoi(argv[2]); //Start server portion server(port); } /////////////////////////////////////////////////////////////////////////////////////////////// //The listen server thread///////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////////////////// void server(int port){ int sd, new_sd; struct sockaddr_in name, cli_name; int sock_opt_val = 1; int cli_len; pthread_t threads[worknum]; //create our pthread id array pthread_t dis[1]; //create our dispatcher array (necessary to create thread) init_mutex_stuff(threads, dis); //initialize mutexes and stuff //Server setup /////////////////////////////////////////////////////// if ((sd = socket (AF_INET, SOCK_STREAM, 0)) < 0) { perror("(servConn): socket() error"); _exit (-1); } if (setsockopt (sd, SOL_SOCKET, SO_REUSEADDR, (char *) &sock_opt_val, sizeof(sock_opt_val)) < 0) { perror ("(servConn): Failed to set SO_REUSEADDR on INET socket"); _exit (-1); } name.sin_family = AF_INET; name.sin_port = htons (port); name.sin_addr.s_addr = htonl(INADDR_ANY); if (bind (sd, (struct sockaddr *)&name, sizeof(name)) < 0) { perror ("(servConn): bind() error"); _exit (-1); } listen (sd, 5); //End of server Setup ////////////////////////////////////////////////// for (;;) { cli_len = sizeof (cli_name); new_sd = accept (sd, (struct sockaddr *) &cli_name, &cli_len); printf ("Assigning new socket descriptor: %d\n", new_sd); inc_clients(); //New client has come in, increment clients add_to_socket_pool(new_sd); //Add client to the pool of sockets if (new_sd < 0) { perror ("(servConn): accept() error"); _exit (-1); } } pthread_exit(NULL); //Quit } //Adds the new socket to the array designated for pthreads in the pool void add_to_socket_pool(int socket){ pthread_mutex_lock(&m_pool_busy); //Lock so that we can check main_pool_busy int i; //If not all our main pool is busy, then allocate to one of them if(main_pool_busy < worknum){ pthread_mutex_unlock(&m_pool_busy); //unlock busy, we no longer need to hold it pthread_mutex_lock(&pool_sockets); //Lock the socket pool array so that we can edit it without worry for(i = 0; i < worknum; i++){ //Find a poolsocket that is -1; then we should put the real socket there. This value will be changed back to -1 when the thread grabs the sockfd if(poolsockets[i] == -1){ poolsockets[i] = socket; pthread_mutex_unlock(&pool_sockets); //unlock our pool array, we don't need it anymore inc_busy(); //Incrememnt busy (locks the mutex itself) pthread_cond_signal(&clientin); //Signal first thread waiting on a client that a client needs to be serviced break; } } } else{ //Dynamic thread creation goes here pthread_mutex_unlock(&m_pool_busy); } } //Increments the client number. If client number goes over worknum, we must dynamically create new pthreads void inc_clients(){ pthread_mutex_lock(&numclients); clients++; pthread_mutex_unlock(&numclients); } //Increments busy void inc_busy(){ pthread_mutex_lock(&m_pool_busy); main_pool_busy++; pthread_mutex_unlock(&m_pool_busy); } //Initialize all of our mutexes at the beginning and create our pthreads void init_mutex_stuff(pthread_t * threads, pthread_t * dis){ pthread_mutex_init(&startservice, NULL); pthread_mutex_init(&numclients, NULL); pthread_mutex_init(&pool_sockets, NULL); pthread_mutex_init(&nonpool_sockets, NULL); pthread_mutex_init(&m_pool_busy, NULL); pthread_mutex_init(&circ, NULL); pthread_cond_init (&clientin, NULL); main_pool_busy = 0; poolsockets = malloc(sizeof(int)*worknum); int threadreturn; //error checking variables long i = 0; //Loop and create pthreads for(i; i < worknum; i++){ threadreturn = pthread_create(&threads[i], NULL, threadpool, (void *) i); poolsockets[i] = -1; if(threadreturn){ perror("Thread pool created unsuccessfully"); _exit(-1); } } pthread_create(&dis[0], NULL, dispatcher, NULL); } ////////////////////////////////////////////////////////////////////////////////////////// /////////Main pool routines ///////////////////////////////////////////////////////////////////////////////////////// void dec_busy(){ pthread_mutex_lock(&m_pool_busy); main_pool_busy--; pthread_mutex_unlock(&m_pool_busy); } void dec_clients(){ pthread_mutex_lock(&numclients); clients--; pthread_mutex_unlock(&numclients); } //This is what our threadpool pthreads will be running. void *threadpool(void * threadid){ long id = (long) threadid; //Id of this thread int i; int socket; int counter = 0; //Try and gain access to the next client that comes in and wait until server signals that a client as arrived while(1){ pthread_mutex_lock(&startservice); //lock start service (required for cond wait) pthread_cond_wait(&clientin, &startservice); //wait for signal from server that client exists pthread_mutex_unlock(&startservice); //unlock mutex. pthread_mutex_lock(&pool_sockets); //Lock the pool socket so we can get the socket fd unhindered/interrupted for(i = 0; i < worknum; i++){ if(poolsockets[i] != -1){ socket = poolsockets[i]; poolsockets[i] = -1; pthread_mutex_unlock(&pool_sockets); } } printf("Thread #%d is past getting the socket\n", id); int incoming = 1; while(counter < 100 && incoming != 0){ char buffer[512]; bzero(buffer,512); int startcounter = 0; incoming = read(socket, buffer, 512); if(buffer[0] != 0){ //client ID:priority:request:arguments char id[100]; long prior; char request[100]; char arg1[100]; char message[100]; char arg2[100]; char * point; point = strtok(buffer, ":"); strcpy(id, point); point = strtok(NULL, ":"); prior = atoi(point); point = strtok(NULL, ":"); strcpy(request, point); point = strtok(NULL, ":"); strcpy(arg1, point); point = strtok(NULL, ":"); if(point != NULL){ strcpy(arg2, point); } int fd; if(strcmp(request, "start_movie") == 0){ int count = 1; while(count <= 100){ char temp[10]; snprintf(temp, 50, "%d\0", count); strcpy(message, "./support/images/"); strcat(message, arg1); strcat(message, temp); strcat(message, ".ppm"); printf("This is message %s to %s\n", message, id); count++; add_to_ring(message, id, prior, counter, socket); //Adds our created message to the ring counter++; } printf("I'm out of the loop\n"); } else if(strcmp(request, "seek_movie") == 0){ int count = atoi(arg2); while(count <= 100){ char temp[10]; snprintf(temp, 10, "%d\0", count); strcpy(message, "./support/images/"); strcat(message, arg1); strcat(message, temp); strcat(message, ".ppm"); printf("This is message %s\n", message); count++; } } //create_message(id, socket, counter, buffer, message); //Creates our message from the input from the client. Stores it in buffer } else{ delete_socket_messages(socket); break; } } counter = 0; close(socket);//Zero out counter again } dec_clients(); //client serviced, decrement clients dec_busy(); //thread finished, decrement busy } //Creates a message void create_message(long threadid, int socket, int counter, char * buffer, char * message){ snprintf(message, strlen(buffer)+15, "%d:%d:%d:%s", threadid, socket, counter, buffer); } //Gets the socket from the message string (maybe I should just pass in the socket to another method) int socket_from_string(char * message){ char * substr1 = strstr(message, ":"); char * substr2 = substr1; substr2++; int occurance = strcspn(substr2, ":"); char sock[10]; strncpy(sock, substr2, occurance); return atoi(sock); } //Adds message to our ring buffer's head void add_to_head(char * message){ printf("Adding to head of ring\n"); mqueue.head->message = malloc(strlen(message)+1); //Allocate space for message strcpy(mqueue.head->message, message); //copy bytes into allocated space } //Adds our message to our ring buffer's tail void add_to_tail(char * message){ printf("Adding to tail of ring\n"); mqueue.tail->message = malloc(strlen(message)+1); //allocate space for message strcpy(mqueue.tail->message, message); //copy bytes into allocated space mqueue.tail->next = malloc(sizeof(struct message)); //allocate space for the next message struct } //Adds a message to our ring void add_to_ring(char * message, char * id, int prior, int mnum, int socket){ //printf("This is message %s:" , message); pthread_mutex_lock(&circ); //Lock the ring buffer pthread_mutex_lock(&numm); //Lock the message count (will need this to make sure we can't fill the buffer over the max slots) if(mqueue.head->message == NULL){ add_to_head(message); //Adds it to head mqueue.head->socket = socket; //Set message socket mqueue.head->priority = prior; //Set its priority (thread id) mqueue.head->mnum = mnum; //Set its message number (used for sorting) mqueue.head->id = malloc(sizeof(id)); strcpy(mqueue.head->id, id); } else if(mqueue.tail->message == NULL){ //This is the problem for dis_m 1 I'm pretty sure add_to_tail(message); mqueue.tail->socket = socket; mqueue.tail->priority = prior; mqueue.tail->mnum = mnum; mqueue.tail->id = malloc(sizeof(id)); strcpy(mqueue.tail->id, id); } else{ mqueue.tail->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.tail->next; add_to_tail(message); mqueue.tail->socket = socket; mqueue.tail->priority = prior; mqueue.tail->mnum = mnum; mqueue.tail->id = malloc(sizeof(id)); strcpy(mqueue.tail->id, id); } mqueue.mcount++; pthread_mutex_unlock(&circ); if(mqueue.mcount >= dis_m){ pthread_mutex_unlock(&numm); pthread_cond_signal(&m); } else{ pthread_mutex_unlock(&numm); } printf("out of add to ring\n"); fflush(stdout); } ////////////////////////////////// //Dispatcher routines ///////////////////////////////// void *dispatcher(){ init_ring(); while(1){ pthread_mutex_lock(&slots); pthread_cond_wait(&m, &slots); pthread_mutex_lock(&numm); pthread_mutex_lock(&circ); printf("Dispatcher to the rescue!\n"); mqueue.head = reorder(mqueue.head, mqueue.tail, mqueue.mcount); //printf("This is the head %s\n", mqueue.head->message); //printf("This is the tail %s\n", mqueue.head->message); fflush(stdout); struct message * pointer = mqueue.head; int count = 0; while(mqueue.head != mqueue.tail && count < dis_m){ printf("Sending to client %s: %s\n", pointer->id, pointer->message); int fd; fd = open(pointer->message, O_RDONLY); char buf[58368]; int bytesRead; printf("This is fd %d\n", fd); bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); fflush(stdout); close(fd); mqueue.mcount--; mqueue.head = mqueue.head->next; free(pointer->message); free(pointer); pointer = mqueue.head; count++; } printf("Sending %s\n", pointer->message); int fd; fd = open(pointer->message, O_RDONLY); printf("This is fd %d\n", fd); printf("I am hhere2\n"); char buf[58368]; int bytesRead; bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); close(fd); mqueue.mcount--; if(mqueue.head != mqueue.tail){ mqueue.head = mqueue.head->next; } else{ mqueue.head->next = malloc(sizeof(struct message)); mqueue.head = mqueue.head->next; mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.head->message = NULL; } free(pointer->message); free(pointer); pthread_mutex_unlock(&numm); pthread_mutex_unlock(&circ); pthread_mutex_unlock(&slots); printf("My dispatcher has defeated evil\n"); } } void init_ring(){ mqueue.head = malloc(sizeof(struct message)); mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.mcount = 0; } struct message * reorder(struct message * begin, struct message * end, int num){ //printf("I am reordering for size %d\n", num); fflush(stdout); int i; if(num == 1){ //printf("Begin: %s\n", begin->message); begin->next = NULL; return begin; } else{ struct message * left = begin; struct message * right; int middle = num/2; for(i = 1; i < middle; i++){ left = left->next; } right = left -> next; left -> next = NULL; //printf("Begin: %s\nLeft: %s\nright: %s\nend:%s\n", begin->message, left->message, right->message, end->message); left = reorder(begin, left, middle); if(num%2 != 0){ right = reorder(right, end, middle+1); } else{ right = reorder(right, end, middle); } return merge(left, right, num); } } struct message * merge(struct message * left, struct message * right, int num){ //printf("I am merginging! left: %s %d, right: %s %dnum: %d\n", left->message,left->priority, right->message, right->priority, num); struct message * start, * point; int lenL= 0; int lenR = 0; int flagL = 0; int flagR = 0; int count = 0; int middle1 = num/2; int middle2; if(num%2 != 0){ middle2 = middle1+1; } else{ middle2 = middle1; } while(lenL < middle1 && lenR < middle2){ count++; //printf("In here for count %d\n", count); if(lenL == 0 && lenR == 0){ if(left->priority < right->priority){ start = left; //Set the start point point = left; //set our enum; left = left->next; //move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else if(left->priority > right->priority){ start = right; point = right; right = right->next; point->next = NULL; lenR++; } else{ if(left->mnum < right->mnum){ ////printf("This is where we are\n"); start = left; //Set the start point point = left; //set our enum; left = left->next; //move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else{ start = right; point = right; right = right->next; point->next = NULL; lenR++; } } } else{ if(left->priority < right->priority){ point->next = left; left = left->next; //move the left pointer point = point->next; point->next = NULL; //Set the next node to NULL lenL++; } else if(left->priority > right->priority){ point->next = right; right = right->next; point = point->next; point->next = NULL; lenR++; } else{ if(left->mnum < right->mnum){ point->next = left; //set our enum; left = left->next; point = point->next;//move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else{ point->next = right; right = right->next; point = point->next; point->next = NULL; lenR++; } } } if(lenL == middle1){ flagL = 1; break; } if(lenR == middle2){ flagR = 1; break; } } if(flagL == 1){ point->next = right; point = point->next; for(lenR; lenR< middle2-1; lenR++){ point = point->next; } point->next = NULL; mqueue.tail = point; } else{ point->next = left; point = point->next; for(lenL; lenL< middle1-1; lenL++){ point = point->next; } point->next = NULL; mqueue.tail = point; } //printf("This is the start %s\n", start->message); //printf("This is mqueue.tail %s\n", mqueue.tail->message); return start; } void delete_socket_messages(int a){ }

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Can I remotely monitor printf results of a C program?

- by Mota

I have a long running C program in which I've started from the Terminal.app using: gdb program_name gdb run I'm using many printf statements to monitor the progress of the program. Unfortunately, the screen of the computer has been frozen since yesterday, but the process is still running. My question is, can I watch the progress of the program (i.e. the results of the printf statements) remotely? I'm not that familiar with the terminal, but I know how to ssh and do some simple terminal tasks. The OS of the machine with the frozen screen is Mac OS 10.6.

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How is conversion of float/double to int handled in printf?

- by Sandip

Consider this program int main() { float f = 11.22; double d = 44.55; int i,j; i = f; //cast float to int j = d; //cast double to int printf("i = %d, j = %d, f = %d, d = %d", i,j,f,d); //This prints the following: // i = 11, j = 44, f = -536870912, d = 1076261027 return 0; } Can someone explain why the casting from double/float to int works correctly in the first case, and does not work when done in printf? This program was compiled on gcc-4.1.2 on 32-bit linux machine. EDIT: Zach's answer seems logical, i.e. use of format specifiers to figure out what to pop off the stack. However then consider this follow up question: int main() { char c = 'd'; // sizeof c is 1, however sizeof character literal // 'd' is equal to sizeof(int) in ANSI C printf("lit = %c, lit = %d , c = %c, c = %d", 'd', 'd', c, c); //this prints: lit = d, lit = 100 , c = d, c = 100 //how does printf here pop off the right number of bytes even when //the size represented by format specifiers doesn't actually match //the size of the passed arguments(char(1 byte) & char_literal(4 bytes)) return 0; } How does this work?

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dynamic lib can't find static lib

- by renyufei

env: gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu9) app: Bin(main) calls dynamic lib(testb.so), and testb.so contains a static lib(libtesta.a). file list: main.c test.h a.c b.c then compile as: gcc -o testa.o -c a.c ar -r libtesta.a testa.o gcc -shared -fPIC -o testb.so b.c gcc -o main main.c -L. -ltesta -ldl then compile success, but runs an error: ./main: symbol lookup error: ./testb.so: undefined symbol: print code as follows: test.h #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <string.h> #include <dlfcn.h> int printa(const char *msg); int printb(const char *msg); a.c #include "test.h" int printa(const char *msg) { printf("\tin printa\n"); printf("\t%s\n", msg); } b.c #include "test.h" int printb(const char *msg) { printf("in printb\n"); printa("called by printb\n"); printf("%s\n", msg); } main.c #include "test.h" int main(int argc, char **argv) { void *handle; int (*dfn)(const char *); printf("before dlopen\n"); handle = dlopen("./testb.so", RTLD_LOCAL | RTLD_LAZY); printf("after dlopen\n"); if (handle == NULL) { printf("dlopen fail: [%d][%s][%s]\n", \ errno, strerror(errno), dlerror()); exit(EXIT_FAILURE); } printf("before dlsym\n"); dfn = dlsym(handle, "printb"); printf("after dlsym\n"); if (dfn == NULL) { printf("dlsym fail: [%d][%s][%s]\n", \ errno, strerror(errno), dlerror()); exit(EXIT_FAILURE); } printf("before dfn\n"); dfn("printb func\n"); printf("after dfn\n"); exit(EXIT_SUCCESS); }

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What does this statement mean ? printf("[%.*s] ", (int) lengths[i],

- by Vivek Goel

I was reading this page http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html there is one line printf("[%.*s] ", (int) lengths[i], row[i] ? row[i] : "NULL"); from code MYSQL_ROW row; unsigned int num_fields; unsigned int i; num_fields = mysql_num_fields(result); while ((row = mysql_fetch_row(result))) { unsigned long *lengths; lengths = mysql_fetch_lengths(result); for(i = 0; i < num_fields; i++) { printf("[%.*s] ", (int) lengths[i], row[i] ? row[i] : "NULL"); } printf("\n"); } what does [%.*s] mean in that code ?

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C code won't compile

- by cc

Please help me to understand why the following code will not compile: #include <stdio.h> //#include <iostream> //using namespace std; int main(void){ int i,k,x,y,run,e,r,s,m,count=0; char numbers[19][19]; for(i=0;i<19;i++){ for (k=0;k<19;k++){ numbers[i][k]='.'; } } void drawB(){ printf(" 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 \n"); printf ("0 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[0][0],numbers[0][1],numbers[0][2],numbers[0][3],numbers[0][4], numbers[0][5],numbers[0][6],numbers[0][7],numbers[0][8],numbers[0][9], numbers[0][10],numbers[1][11],numbers[1][12],numbers[1][13],numbers[0][14] ,numbers[0][15],numbers[0][16],numbers[0][17],numbers[0][18]); printf ("1 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[1][0],numbers[1][1],numbers[1][2],numbers[1][3],numbers[1][4], numbers[1][5],numbers[1][6],numbers[1][7],numbers[1][8],numbers[1][9], numbers[1][10],numbers[1][11],numbers[1][12],numbers[1][13],numbers[1][14] ,numbers[1][15],numbers[1][16],numbers[1][17],numbers[1][18]); printf ("2 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" numbers[2][0],numbers[2][1],numbers[2][2],numbers[2][3],numbers[2][4], numbers[2][5],numbers[2][6],numbers[2][7],numbers[2][8],numbers[2][9], numbers[2][10],numbers[2][11],numbers[2][12],numbers[2][13],numbers[2][14] ,numbers[2][15],numbers[2][16],numbers[2][17],numbers[2][18]); printf ("3 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[3][0],numbers[3][1],numbers[3][2],numbers[3][3],numbers[3][4], numbers[3][5],numbers[3][6],numbers[3][7],numbers[3][8],numbers[3][9], numbers[3][10],numbers[3][11],numbers[3][12],numbers[3][13],numbers[3][14] ,numbers[3][15],numbers[3][16],numbers[3][17],numbers[3][18]); printf ("4 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[4][0],numbers[4][1],numbers[4][2],numbers[4][3],numbers[4][4], numbers[4][5],numbers[4][6],numbers[4][7],numbers[4][8],numbers[4][9], numbers[4][10],numbers[4][11],numbers[4][12],numbers[4][13],numbers[4][14] ,numbers[4][15],numbers[4][16],numbers[4][17],numbers[4][18]); printf ("5 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[5][0],numbers[5][1],numbers[5][2],numbers[5][3],numbers[5][4], numbers[5][5],numbers[5][6],numbers[5][7],numbers[5][8],numbers[5][9], numbers[5][10],numbers[5][11],numbers[5][12],numbers[5][13],numbers[5][14] ,numbers[5][15],numbers[5][16],numbers[5][17],numbers[5][18]); printf ("6 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[6][0],numbers[6][1],numbers[6][2],numbers[6][3],numbers[6][4], numbers[6][5],numbers[6][6],numbers[6][7],numbers[6][8],numbers[6][9], numbers[6][10],numbers[6][11],numbers[6][12],numbers[6][13],numbers[6][14] ,numbers[6][15],numbers[6][16],numbers[6][17],numbers[6][18]); printf ("7 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[7][0],numbers[7][1],numbers[7][2],numbers[7][3],numbers[7][4], numbers[7][5],numbers[7][6],numbers[7][7],numbers[7][8],numbers[7][9], numbers[7][10],numbers[7][11],numbers[7][12],numbers[7][13],numbers[7][14] ,numbers[7][15],numbers[7][16],numbers[7][17],numbers[7][18]); printf ("8 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[8][0],numbers[8][1],numbers[8][2],numbers[8][3],numbers[8][4], numbers[8][5],numbers[8][6],numbers[8][7],numbers[8][8],numbers[8][9], numbers[8][10],numbers[8][11],numbers[8][12],numbers[8][13],numbers[8][14] ,numbers[8][15],numbers[8][16],numbers[8][17],numbers[8][18]); printf ("9 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[9][0],numbers[9][1],numbers[9][2],numbers[9][3],numbers[9][4], numbers[9][5],numbers[9][6],numbers[9][7],numbers[9][8],numbers[9][9], numbers[9][10],numbers[9][11],numbers[9][12],numbers[9][13],numbers[9][14] ,numbers[9][15],numbers[9][16],numbers[9][17],numbers[9][18]); printf ("0 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[10][0],numbers[10][1],numbers[10][2],numbers[10][3],numbers[10][4], numbers[10][5],numbers[10][6],numbers[10][7],numbers[10][8],numbers[10][9], numbers[10][10],numbers[10][11],numbers[10][12],numbers[10][13],numbers[10][14] ,numbers[10][15],numbers[10][16],numbers[10][17],numbers[10][18]); printf ("1 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[11][0],numbers[11][1],numbers[11][2],numbers[11][3],numbers[11][4], numbers[11][5],numbers[11][6],numbers[11][7],numbers[11][8],numbers[11][9], numbers[11][10],numbers[11][11],numbers[11][12],numbers[11][13],numbers[11][14] ,numbers[11][15],numbers[11][16],numbers[11][17],numbers[11][18]); printf ("2 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[12][0],numbers[12][1],numbers[12][2],numbers[12][3],numbers[12][4], numbers[12][5],numbers[12][6],numbers[12][7],numbers[12][8],numbers[12][9], numbers[12][10],numbers[12][11],numbers[12][12],numbers[12][13],numbers[12][14] ,numbers[12][15],numbers[12][16],numbers[12][17],numbers[12][18]); printf ("3 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[13][0],numbers[13][1],numbers[13][2],numbers[13][3],numbers[13][4], numbers[13][5],numbers[13][6],numbers[13][7],numbers[13][8],numbers[13][9], numbers[13][10],numbers[13][11],numbers[13][12],numbers[13][13],numbers[13][14] ,numbers[13][15],numbers[13][16],numbers[13][17],numbers[13][18]); printf ("4 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[14][0],numbers[14][1],numbers[14][2],numbers[14][3],numbers[14][4], numbers[14][5],numbers[14][6],numbers[14][7],numbers[14][8],numbers[14][9], numbers[14][10],numbers[14][11],numbers[14][12],numbers[14][13],numbers[14][14] ,numbers[14][15],numbers[14][16],numbers[14][17],numbers[14][18]); printf ("5 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[15][0],numbers[15][1],numbers[15][2],numbers[15][3],numbers[15][4], numbers[15][5],numbers[15][6],numbers[15][7],numbers[15][8],numbers[15][9], numbers[15][10],numbers[15][11],numbers[15][12],numbers[15][13],numbers[15][14] ,numbers[15][15],numbers[15][16],numbers[15][17],numbers[15][18]); printf ("6 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[16][0],numbers[16][1],numbers[16][2],numbers[16][3],numbers[16][4], numbers[16][5],numbers[16][6],numbers[16][7],numbers[16][8],numbers[16][9], numbers[16][10],numbers[16][11],numbers[16][12],numbers[16][13],numbers[16][14] ,numbers[16][15],numbers[16][16],numbers[16][17],numbers[16][18]); printf ("7 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[17][0],numbers[17][1],numbers[17][2],numbers[17][3],numbers[17][4], numbers[17][5],numbers[17][6],numbers[17][7],numbers[17][8],numbers[17][9], numbers[17][10],numbers[17][11],numbers[17][12],numbers[17][13],numbers[17][14] ,numbers[17][15],numbers[17][16],numbers[17][17],numbers[17][18]); printf ("8 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[18][0],numbers[18][1],numbers[18][2],numbers[18][3],numbers[18][4], numbers[18][5],numbers[18][6],numbers[18][7],numbers[18][8],numbers[18][9], numbers[18][10],numbers[18][11],numbers[18][12],numbers[18][13],numbers[18][14] ,numbers[18][15],numbers[18][16],numbers[18][17],numbers[18][18]); } void checkSurrounded (int x,int y){ //numbers [x-1,y-1 ] , numbers [x-1,y ] , numbers [x-1,y+1 ] //numbers [x,y-1 ] , numbers [x,y ] , numbers [x,y+1 ] //numbers [x+1,y-1, ] , numbers [x+1,y ] , numbers [x+1,y+1 ] if(numbers[x][y]=='A'){ if((numbers[x-1][y-1]=='B') && (numbers[x-1][y]=='B') && (numbers[x-1][y+1]=='B') && (numbers[x][y-1]=='B') && (numbers[x][y+1]=='B') && (numbers[x+1][y-1]=='B') && (numbers[x+1][y]=='B')){ numbers[x][y]='B';} } if(numbers[x][y]=='B'){ if((numbers[x-1][y-1]=='A') && (numbers[x-1][y]=='A') && (numbers[x-1][y+1]=='A') && (numbers[x][y-1]=='A') && (numbers[x][y+1]=='A') && (numbers[x+1][y-1]=='A') && (numbers[x+1][y]=='A')){ numbers[x][y]='A'; } } } /** void checkArea(){ //detect enemy stone //store in array //find adjacent enemy stones // store the enemy stones in the array //keep on doing this until there are no more enemy stones that are adjacent for (s=0;s<19;s++) { for (m=0;m<19;m++) { if (numbers[s][m]=='A'){ count++; } } } }//end fn void checkAdjacent(int x, int y){ if (numbers [x][y]=='A'){ if((numbers[x][y-1]=='B' && numbers [x-1][y]=='B' && numbers[x][y+1]=='B' && numbers[x+1][y]=='B')){ } } } void getUserInput(){ int run=1; while(run){ printf("Enter x coordinate\n"); scanf("%d",&x); printf("Enter y coordinate\n"); scanf("%d",&y); if((x>18 || y>18 || x<0 || y<0) && !( numbers[x][y]=='.' )){ printf("invalid imput\n"); } else{ numbers[x][y]='B'; run=0; drawB(); } } } */ void getCupInput(){ //go through borad //starting from [0][0] //stop at first player stone //save as target x and target y //surround target x and target y //if already surrounded //start looking in borad again from last position //at end of board reset to [0][0] for(s=0;s<19;s++) { for(m=0;m<19;m++) { if (numbers[s][m]==0){ count++; } } } x=x-2; y=y+2; numbers[x][y]='A'; drawB(); } while(1){ //getUserInput(); getCupInput(); } system("pause"); return 0; }

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seg fault at the end of program after executing everything?

- by Fantastic Fourier

Hello all, I wrote a quick program which executes every statement before giving a seg fault error. struct foo { int cat; int * dog; }; void bar (void * arg) { printf("o hello bar\n"); struct foo * food = (struct foo *) arg; printf("cat meows %i\n", food->cat); printf("dog barks %i\n", *(food->dog)); } void main() { int cat = 4; int * dog; dog = &cat; printf("cat meows %i\n", cat); printf("dog barks %i\n", *dog); struct foo * food; food->cat = cat; food->dog = dog; printf("cat meows %i\n", food->cat); printf("dog barks %i\n", *(food->dog)); printf("time for foo!\n"); bar(food); printf("begone!\n"); cat = 5; printf("cat meows %i\n", cat); printf("dog barks %i\n", *dog); // return 0; } which gives a result of cat meows 4 dog barks 4 cat meows 4 dog barks 4 time for foo! o hello bar cat meows 4 dog barks 4 begone! cat meows 5 dog barks 5 Segmentation fault (core dumped) I'm not really sure why it seg faults at the end? Any comments/insights are deeply appreciated.

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stdio data from write not making it into a file

- by user1551209

I'm having a problem with using stdio commands for manipulating data in a file. I short, when I write data into a file, write returns an int indicating that it was successful, but when I read it back out I only get the old data. Here's a stripped down version of the code: fd = open(filename,O_RDWR|O_APPEND); struct dE *cDE = malloc(sizeof(struct dE)); //Read present data printf("\nreading values at %d\n",off); printf("SeekStatus <%d>\n",lseek(fd,off,SEEK_SET)); printf("ReadStatus <%d>\n",read(fd,cDE,deSize)); printf("current Key/Data <%d/%s>\n",cDE->key,cDE->data); printf("\nwriting new values\n"); //Change the values locally cDE->key = //something new cDE->data = //something new //Write them back printf("SeekStatus <%d>\n",lseek(fd,off,SEEK_SET)); printf("WriteStatus <%d>\n",write(fd,cDE,deSize)); //Re-read to make sure that it got written back printf("\nre-reading values at %d\n",off); printf("SeekStatus <%d>\n",lseek(fd,off,SEEK_SET)); printf("ReadStatus <%d>\n",read(fd,cDE,deSize)); printf("current Key/Data <%d/%s>\n",cDE->key,cDE->data); Furthermore, here's the dE struct in case you're wondering: struct dE { int key; char data[DataSize]; }; This prints: reading values at 1072 SeekStatus <1072> ReadStatus <32> current Key/Data <27/old> writing new values SeekStatus <1072> WriteStatus <32> re-reading values at 1072 SeekStatus <1072> ReadStatus <32> current Key/Data <27/old>

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i am using winsock2.h in c language the following errors are unuderstandable help required?

- by moon

i am going to paste here my code an errors :::: #include "stdio.h" #include "winsock2.h" #define SIO_RCVALL _WSAIOW(IOC_VENDOR,1) //this removes the need of mstcpip.h void StartSniffing (SOCKET Sock); //This will sniff here and there void ProcessPacket (unsigned char* , int); //This will decide how to digest void PrintIpHeader (unsigned char* , int); void PrintUdpPacket (unsigned char* , int); void ConvertToHex (unsigned char* , unsigned int); void PrintData (unsigned char* , int); //IP Header Structure typedef struct ip_hdr { unsigned char ip_header_len:4; // 4-bit header length (in 32-bit words) normally=5 (Means 20 Bytes may be 24 also) unsigned char ip_version :4; // 4-bit IPv4 version unsigned char ip_tos; // IP type of service unsigned short ip_total_length; // Total length unsigned short ip_id; // Unique identifier unsigned char ip_frag_offset :5; // Fragment offset field unsigned char ip_more_fragment :1; unsigned char ip_dont_fragment :1; unsigned char ip_reserved_zero :1; unsigned char ip_frag_offset1; //fragment offset unsigned char ip_ttl; // Time to live unsigned char ip_protocol; // Protocol(TCP,UDP etc) unsigned short ip_checksum; // IP checksum unsigned int ip_srcaddr; // Source address unsigned int ip_destaddr; // Source address } IPV4_HDR; //UDP Header Structure typedef struct udp_hdr { unsigned short source_port; // Source port no. unsigned short dest_port; // Dest. port no. unsigned short udp_length; // Udp packet length unsigned short udp_checksum; // Udp checksum (optional) } UDP_HDR; //ICMP Header Structure typedef struct icmp_hdr { BYTE type; // ICMP Error type BYTE code; // Type sub code USHORT checksum; USHORT id; USHORT seq; } ICMP_HDR; FILE *logfile; int tcp=0,udp=0,icmp=0,others=0,igmp=0,total=0,i,j; struct sockaddr_in source,dest; char hex[2]; //Its free! IPV4_HDR *iphdr; UDP_HDR *udpheader; int main() { SOCKET sniffer; struct in_addr addr; int in; char hostname[100]; struct hostent *local; WSADATA wsa; //logfile=fopen("log.txt","w"); //if(logfile==NULL) printf("Unable to create file."); //Initialise Winsock printf("\nInitialising Winsock..."); if (WSAStartup(MAKEWORD(2,2), &wsa) != 0) { printf("WSAStartup() failed.\n"); return 1; } printf("Initialised"); //Create a RAW Socket printf("\nCreating RAW Socket..."); sniffer = socket(AF_INET, SOCK_RAW, IPPROTO_IP); if (sniffer == INVALID_SOCKET) { printf("Failed to create raw socket.\n"); return 1; } printf("Created."); //Retrive the local hostname if (gethostname(hostname, sizeof(hostname)) == SOCKET_ERROR) { printf("Error : %d",WSAGetLastError()); return 1; } printf("\nHost name : %s \n",hostname); //Retrive the available IPs of the local host local = gethostbyname(hostname); printf("\nAvailable Network Interfaces : \n"); if (local == NULL) { printf("Error : %d.\n",WSAGetLastError()); return 1; } for (i = 0; local->h_addr_list[i] != 0; ++i) { memcpy(&addr, local->h_addr_list[i], sizeof(struct in_addr)); printf("Interface Number : %d Address : %s\n",i,inet_ntoa(addr)); } printf("Enter the interface number you would like to sniff : "); scanf("%d",&in); memset(&dest, 0, sizeof(dest)); memcpy(&dest.sin_addr.s_addr,local->h_addr_list[in],sizeof(dest.sin_addr.s_addr)); dest.sin_family = AF_INET; dest.sin_port = 0; printf("\nBinding socket to local system and port 0 ..."); if (bind(sniffer,(struct sockaddr *)&dest,sizeof(dest)) == SOCKET_ERROR) { printf("bind(%s) failed.\n", inet_ntoa(addr)); return 1; } printf("Binding successful"); //Enable this socket with the power to sniff : SIO_RCVALL is the key Receive ALL ;) j=1; printf("\nSetting socket to sniff..."); if (WSAIoctl(sniffer, SIO_RCVALL,&j, sizeof(j), 0, 0,(LPDWORD)&in,0, 0) == SOCKET_ERROR) { printf("WSAIoctl() failed.\n"); return 1; } printf("Socket set."); //Begin printf("\nStarted Sniffing\n"); printf("Packet Capture Statistics...\n"); StartSniffing(sniffer); //Happy Sniffing //End closesocket(sniffer); WSACleanup(); return 0; } void StartSniffing(SOCKET sniffer) { unsigned char *Buffer = ( unsigned char *)malloc(65536); //Its Big! int mangobyte; if (Buffer == NULL) { printf("malloc() failed.\n"); return; } do { mangobyte = recvfrom(sniffer,(char *)Buffer,65536,0,0,0); //Eat as much as u can if(mangobyte > 0) ProcessPacket(Buffer, mangobyte); else printf( "recvfrom() failed.\n"); } while (mangobyte > 0); free(Buffer); } void ProcessPacket(unsigned char* Buffer, int Size) { iphdr = (IPV4_HDR *)Buffer; ++total; switch (iphdr->ip_protocol) //Check the Protocol and do accordingly... { case 1: //ICMP Protocol ++icmp; //PrintIcmpPacket(Buffer,Size); break; case 2: //IGMP Protocol ++igmp; break; case 6: //TCP Protocol ++tcp; //PrintTcpPacket(Buffer,Size); break; case 17: //UDP Protocol ++udp; PrintUdpPacket(Buffer,Size); break; default: //Some Other Protocol like ARP etc. ++others; break; } printf("TCP : %d UDP : %d ICMP : %d IGMP : %d Others : %d Total : %d\r",tcp,udp,icmp,igmp,others,total); } void PrintIpHeader (unsigned char* Buffer, int Size) { unsigned short iphdrlen; iphdr = (IPV4_HDR *)Buffer; iphdrlen = iphdr->ip_header_len*4; memset(&source, 0, sizeof(source)); source.sin_addr.s_addr = iphdr->ip_srcaddr; memset(&dest, 0, sizeof(dest)); dest.sin_addr.s_addr = iphdr->ip_destaddr; fprintf(logfile,"\n"); fprintf(logfile,"IP Header\n"); fprintf(logfile," |-IP Version : %d\n",(unsigned int)iphdr->ip_version); fprintf(logfile," |-IP Header Length : %d DWORDS or %d Bytes\n",(unsigned int)iphdr->ip_header_len); fprintf(logfile," |-Type Of Service : %d\n",(unsigned int)iphdr->ip_tos); fprintf(logfile," |-IP Total Length : %d Bytes(Size of Packet)\n",ntohs(iphdr->ip_total_length)); fprintf(logfile," |-Identification : %d\n",ntohs(iphdr->ip_id)); fprintf(logfile," |-Reserved ZERO Field : %d\n",(unsigned int)iphdr->ip_reserved_zero); fprintf(logfile," |-Dont Fragment Field : %d\n",(unsigned int)iphdr->ip_dont_fragment); fprintf(logfile," |-More Fragment Field : %d\n",(unsigned int)iphdr->ip_more_fragment); fprintf(logfile," |-TTL : %d\n",(unsigned int)iphdr->ip_ttl); fprintf(logfile," |-Protocol : %d\n",(unsigned int)iphdr->ip_protocol); fprintf(logfile," |-Checksum : %d\n",ntohs(iphdr->ip_checksum)); fprintf(logfile," |-Source IP : %s\n",inet_ntoa(source.sin_addr)); fprintf(logfile," |-Destination IP : %s\n",inet_ntoa(dest.sin_addr)); } void PrintUdpPacket(unsigned char *Buffer,int Size) { unsigned short iphdrlen; iphdr = (IPV4_HDR *)Buffer; iphdrlen = iphdr->ip_header_len*4; udpheader = (UDP_HDR *)(Buffer + iphdrlen); fprintf(logfile,"\n\n***********************UDP Packet*************************\n"); PrintIpHeader(Buffer,Size); fprintf(logfile,"\nUDP Header\n"); fprintf(logfile," |-Source Port : %d\n",ntohs(udpheader->source_port)); fprintf(logfile," |-Destination Port : %d\n",ntohs(udpheader->dest_port)); fprintf(logfile," |-UDP Length : %d\n",ntohs(udpheader->udp_length)); fprintf(logfile," |-UDP Checksum : %d\n",ntohs(udpheader->udp_checksum)); fprintf(logfile,"\n"); fprintf(logfile,"IP Header\n"); PrintData(Buffer,iphdrlen); fprintf(logfile,"UDP Header\n"); PrintData(Buffer+iphdrlen,sizeof(UDP_HDR)); fprintf(logfile,"Data Payload\n"); PrintData(Buffer+iphdrlen+sizeof(UDP_HDR) ,(Size - sizeof(UDP_HDR) - iphdr->ip_header_len*4)); fprintf(logfile,"\n###########################################################"); } void PrintData (unsigned char* data , int Size) { for(i=0 ; i < Size ; i++) { if( i!=0 && i%16==0) //if one line of hex printing is complete... { fprintf(logfile," "); for(j=i-16 ; j<i ; j++) { if(data[j]>=32 && data[j]<=128) fprintf(logfile,"%c",(unsigned char)data[j]); //if its a number or alphabet else fprintf(logfile,"."); //otherwise print a dot } fprintf(logfile,"\n"); } if(i%16==0) fprintf(logfile," "); fprintf(logfile," %02X",(unsigned int)data[i]); if( i==Size-1) //print the last spaces { for(j=0;j<15-i%16;j++) fprintf(logfile," "); //extra spaces fprintf(logfile," "); for(j=i-i%16 ; j<=i ; j++) { if(data[j]>=32 && data[j]<=128) fprintf(logfile,"%c",(unsigned char)data[j]); else fprintf(logfile,"."); } fprintf(logfile,"\n"); } } } following are the errors Error 1 error LNK2019: unresolved external symbol __imp__WSACleanup@0 referenced in function _main sniffer.obj sniffer test Error 2 error LNK2019: unresolved external symbol __imp__closesocket@4 referenced in function _main sniffer.obj sniffer test Error 3 error LNK2019: unresolved external symbol __imp__WSAIoctl@36 referenced in function _main sniffer.obj sniffer test Error 4 error LNK2019: unresolved external symbol __imp__bind@12 referenced in function _main sniffer.obj sniffer test Error 5 error LNK2019: unresolved external symbol __imp__inet_ntoa@4 referenced in function _main sniffer.obj sniffer test Error 6 error LNK2019: unresolved external symbol __imp__gethostbyname@4 referenced in function _main sniffer.obj sniffer test Error 7 error LNK2019: unresolved external symbol __imp__WSAGetLastError@0 referenced in function _main sniffer.obj sniffer test Error 8 error LNK2019: unresolved external symbol __imp__gethostname@8 referenced in function _main sniffer.obj sniffer test Error 9 error LNK2019: unresolved external symbol __imp__socket@12 referenced in function _main sniffer.obj sniffer test Error 10 error LNK2019: unresolved external symbol __imp__WSAStartup@8 referenced in function _main sniffer.obj sniffer test Error 11 error LNK2019: unresolved external symbol __imp__recvfrom@24 referenced in function "void __cdecl StartSniffing(unsigned int)" (?StartSniffing@@YAXI@Z) sniffer.obj sniffer test Error 12 error LNK2019: unresolved external symbol __imp__ntohs@4 referenced in function "void __cdecl PrintIpHeader(unsigned char *,int)" (?PrintIpHeader@@YAXPAEH@Z) sniffer.obj sniffer test Error 13 fatal error LNK1120: 12 unresolved externals E:\CWM\sniffer test\Debug\sniffer test.exe sniffer test

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