Search Results

Search found 3255 results on 131 pages for 'pointers'.

Page 9/131 | < Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >

  • Using Ops Center to Provision Solaris using a Card-Based NIC

    - by Larry Wake
    Scott Dickson writes:  "Here's what I want to do:  I have a Sun Fire T2000 server with a Quad-GbE nxge card installed.  The only network is connected to port 2 on that card rather than the built-in network interfaces.  I want to install Solaris on it across the network, either Solaris 10 or Solaris 11." See what he did, using Oracle Enterprise Manager Ops Center 12c. [Read More]

    Read the article

  • Great Solaris 10 features paving the way to Solaris 11

    - by Larry Wake
    Karoly Vegh writes on the Oracle Systems Blog Austria about what you can do with Solaris 10 today that will get you ready for Solaris 11. Even today, many people still use Solaris 10 as if it were a patch update to Solaris 8 or 9, missing out on the power behind Live Upgrade, Zones, resource management, and ZFS. Learning more about these will help set your feet on the road to the even more sophisticated capabilities of Oracle Solaris 11. [Read More]

    Read the article

  • If you favor "T *var", do you ever write "T*"?

    - by Roger Pate
    Thinking about where we place our asterisks; how do those that prefer to keep the "pointerness" away from the type and with the identifier (int *i) write code when the identifier is missing? void f(int*); // 1 void f(int *); // 2 The former seems much more common, no matter what your preference when with the identifier. Is this a special case? What makes it an exception? However, the first still isn't universal, because I have seen the latter style. Besides consistency along the lines of "there's always a space with the identifier, so we have one without", are there any other reasons to prefer it? What about casts or array and function types? How would you re-write these: (void*)var /*or*/ (void *)var int[3] /*or*/ int [3] // more relevant in C++ than C: Example<int[3]> void(int) /*or*/ void (int) // more relevant in C++ than C: std::function<void(int)> The latter two would rarely, if ever, be used in C, but are seen with C++ templates.

    Read the article

  • Simple C: atof giving wrong value [migrated]

    - by Doc
    I have a program that reads input from a singe line(string obviously) and organizes it into arrays. The problem I have is that at one point the program reads two different values and returns the first one twice. Initially I thought the program was reading the same value twice but when I tested it turned out that it got the correct one but is inputting the wrong one. for example Input: 2 0.90 0.75 0.7 0.65 sorry to snip it (while(fgets (string[test], sizeof(string[test]),ifp)) pch = strtok_r(NULL, " ", &prog); tem3 = atoi(pch); while (loop<tem3) { pch=strtok_r(NULL," ",&prog); venseatfloat[test][loop][DISCOUNT][OCCUPIED]=(float)atof(pch); printf("%f is discount\t",venseatfloat[test][loop][DISCOUNT][OCCUPIED]); pch=strtok_r(NULL, " ", &prog); strcpy(temp, pch); venseatfloat[test][loop][REGULAR][OCCUPIED]=(float)atof(pch); printf("%s is the string but %.3f is regular\n", temp ,venseatfloat[test][loop][DISCOUNT][OCCUPIED]); loop++; } output: >0.900000 is discount 0.75 is the string but 0.900 is regular >0.700000 is discount 0.65 is the string but 0.700 is regular What is going on?

    Read the article

  • How can I malloc an array of struct to do the following using file operation?

    - by RHN
    How can malloc an array of struct to do the following using file operation? the file is .txt input in the file is like: 10 22 3.3 33 4.4 I want to read the first line from the file and then I want to malloc an array of input structures equal to the number of lines to be read in from the file. Then I want to read in the data from the file and into the array of structures malloc. Later on I want to store the size of the array into the input variable size. return an array.After this I want to create another function that print out the data in the input variable in the same form like input file and suppose a function call clean_data will free the malloc memory at the end. I have tried somthing like: struct input { int a; float b,c; } struct input* readData(char *filename,int *size); int main() { return 0; } struct input* readData(char *filename,int *size) { char filename[] = "input.txt"; FILE *fp = fopen(filename, "r"); int num; while(!feof(fp)) { fscanf(fp,"%f", &num); struct input *arr = (struct input*)malloc(sizeof(struct input)); } }

    Read the article

  • Storing a pass-by-reference parameter as a pointer - Bad practice?

    - by Karl Nicoll
    I recently came across the following pattern in an API I've been forced to use: class SomeObject { public: // Constructor. SomeObject(bool copy = false); // Set a value. void SetValue(const ComplexType &value); private: bool m_copy; ComplexType *m_pComplexType; ComplexType m_complexType; }; // ------------------------------------------------------------ SomeObject::SomeObject(bool copy) : m_copy(copy) { } // ------------------------------------------------------------ void SomeObject::SetValue(const ComplexType &value) { if (m_copy) m_complexType.assign(value); else m_pComplexType = const_cast<ComplexType *>(&value); } The background behind this pattern is that it is used to hold data prior to it being encoded and sent to a TCP socket. The copy weirdness is designed to make the class SomeObject efficient by only holding a pointer to the object until it needs to be encoded, but also provide the option to copy values if the lifetime of the SomeObject exceeds the lifetime of a ComplexType. However, consider the following: SomeObject SomeFunction() { ComplexType complexTypeInstance(1); // Create an instance of ComplexType. SomeObject encodeHelper; encodeHelper.SetValue(complexTypeInstance); // Okay. return encodeHelper; // Uh oh! complexTypeInstance has been destroyed, and // now encoding will venture into the realm of undefined // behaviour! } I tripped over this because I used the default constructor, and this resulted in messages being encoded as blank (through a fluke of undefined behaviour). It took an absolute age to pinpoint the cause! Anyway, is this a standard pattern for something like this? Are there any advantages to doing it this way vs overloading the SetValue method to accept a pointer that I'm missing? Thanks!

    Read the article

  • C++ function returning pointer, why does this work ? [migrated]

    - by nashmaniac
    So heres a simple c++ function what it does it take an array of characters as its argument and a integer n and then creates a new character array with only n elements of the array. char * cutString(char * ch , int n){ char * p = new char[n]; int i ; for(i = 0 ; i < n ; i++) p[i] = ch[i]; while(i <= n ){ p[i++] = '\0'; } return p ; } this works just fine but if I change char * p = new char[n]; to char p[n]; I see funny characters what happens ? What difference does the former make also p is a temporary variable then how does the function returns it alright ?

    Read the article

  • Please help me debug this little C program on dynamic two-dimensional array? [migrated]

    - by azhi
    I am a newbie here. I have written a little C program, which is to create a two-dimensional matrix. Here is the code: #include <stdio.h> #include <stdlib.h> int **CreatMatrix(int m,int n){ int **Matrix; int i; Matrix=(int**)malloc(m*sizeof(int*)); for(i=0;i<m;i++){ Matrix[i]=(int*)malloc(n*sizeof(int)); } return Matrix; } int main(){ int m,n; int **A; printf("Please input the size of the Matrix: "); scanf("%d%d",&m,&n); A=CreatMatrix(m,n); printf("Please input the entries of the Matrix, which should be integers!\n"); int i,j; for(i=0;i<m;i++){ for(j=0;j<n;j++){ scanf("%d",&A[i][j]); } } printf("The Matrix that you input is:\n"); for(i=0;i<m;i++){ for(j=0;j<n;j++){ printf("%3d ",A[i][j]); } printf("\n"); } for(i=0;i<m;i++) free(A[i]); free(A); } I have run it, and it works fine. But I am not sure if it is right? Can anyone help me debug it?

    Read the article

  • Different types for declaring pointer variables

    - by viswanathan
    Consider the below 2 declarations. appears next to the datatype and not next to variable char* ptr1, * ptr2, * ptr3; //all 3 are pointers appears next to the variable and not next to datatype char *ptr1,*ptr2,*ptr3; //again al 3 are pointers Is there any difference in intepretation between the 2 declarations. I know there is no difference in the variables. What is the rationale behind introducing void pointers?

    Read the article

  • Why is address zero used for null pointer?

    - by Joel
    In C (or C++ for that matter), pointers are special if they have the value zero: I am adviced to set pointers to zero after freeing their memory, because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid etc. But since memory addressing starts at 0, isn't 0 just as a valid address as any other? How can 0 be used for handling null pointers if that is the case? Why isn't a negative number null instead?

    Read the article

  • Refcounted pointers on iPhone

    - by anon
    1) Refcounted pointers need stack variables to have constructors / destructors called at predictable places. 2) Objective-C, afaik, does not support the above. 3) The cocoa libraries are bound in Objective-C, not C++. Thus, my question: is there a easy way to use the Cocoa libraries, yet still have most of my app in C++ (and thus use my refcounted pointers)? Thanks! (iPhone in the title since this is mainly targeted at the iPhone)

    Read the article

  • Function pointers with default parameters in C++

    - by user308926
    How does C++ handle function pointers in relation to functions with defaulted parameters? If I have: void foo(int i, float f = 0.0f); void bar(int i, float f); void (*func_ptr1)(int); void (*func_ptr2)(int, float); void (*func_ptr3)(int, float = 10.0f); Which function pointers can I use in relation to which function?

    Read the article

  • Detecting use after free() on windows. (dangling pointers)

    - by The Rook
    I'm trying to detect "Use after free()" bugs, otherwise known as "Dangling pointers". I know Valgrind can be used to detect "Use after free" bugs on the *nix platform, but what about windows? What if I don't have the source? Is there a better program than Valgrind for detecting all dangling pointers in a program? A free and open source would be preferred , but I'll use a commercial solution if it will get the job done.

    Read the article

  • Getting size of a specific byte array from an array of pointers to bytes

    - by Pat James
    In the following example c code, used in an Arduino project, I am looking for the ability to get the size of a specific byte array within an array of pointers to bytes, for example void setup() { Serial.begin(9600); // for debugging byte zero[] = {8, 169, 8, 128, 2,171,145,155,141,177,187,187,2,152,2,8,134,199}; byte one[] = {8, 179, 138, 138, 177 ,2,146, 8, 134, 8, 194,2,1,14,199,7, 145, 8,131, 8,158,8,187,187,191}; byte two[] = {29,7,1,8, 169, 8, 128, 2,171,145,155,141,177,187,187,2,152,2,8,134,199, 2, 2, 8, 179, 138, 138, 177 ,2,146, 8, 134, 8, 194,2,1,14,199,7, 145, 8,131, 8,158,8,187,187,191}; byte* numbers[3] = {zero, one, two }; function(numbers[1], sizeof(numbers[1])/sizeof(byte)); //doesn't work as desired, always passes 2 as the length function(numbers[1], 25); //this works } void loop() { } void function( byte arr[], int len ) { Serial.print("length: "); Serial.println(len); for (int i=0; i<len; i++){ Serial.print("array element "); Serial.print(i); Serial.print(" has value "); Serial.println((int)arr[i]); } } In this code, I understand that sizeof(numbers1)/sizeof(byte)) doesn't work because numbers1 is a pointer and not the byte array value. Is there a way in this example that I can, at runtime, get at the length of a specific (runtime-determined) byte array within an array of pointers to bytes? Understand that I am limited to developing in c (or assembly) for an Arduino environment. Also open to other suggestions rather than the array of pointers to bytes. The overall objective is to organize lists of bytes which can be retrieved, with length, at runtime.

    Read the article

  • How to call functions inside a C dll which take pointers as arguments from C#

    - by AndrejaKo
    Hi people, this is my first post here! I'm trying to make a windows forms program using C# which will use a precompiled C library. It will access a smart card and provide output from it. For the library, I have a .dll, .lib and .h and no source. In the .h file there are several structs defined. Most interesting functions of the .dll expect pointers to allocated structs as arguments. I've been calling functions inside the .dll like this: For example function EID_API int WINAPI EidStartup(int nApiVersion); would be called like this [DllImport("CelikApi.dll")]//the name of the .dll public static extern int EidStartup(int nApiVersion); Now my problem is that I can't find equivalent of C's pointers which point to dynamically allocated structures in memory in C#, so I don't know what to pass as argument to functions which take C pointers. I don't have much experience in C#, but to me its use looked as the easiest way of making the program I need. I tried with C++, but Visual Studio 2010 doesn't have IntelliSense for C++/CLR. If you can point me to something better, feel free to do so.

    Read the article

  • C++ Conceptual problem with (Pointer) Pointers

    - by Ptr
    I have a structure usually containing a pointer to an int. However, in some special cases, it is necessary that this int pointer points to another pointer which then points to an int. Wow: I mentioned the word pointer 5 times so far! Is this even possible? I thought about it that way: Instead of using a second int pointer, which is most likely not possible as my main int pointer can only point to an int and not to another int pointer, I could make it a reference like this: int intA = 1; int intB = 2; int& intC = intB; int* myPointers[ 123 ]; myPointers[ 0 ] = &intA; myPointers[ 1 ] = &intB; myPointers[ 3 ] = &intC; So the above would do what I want: The reference to intB (intC) behaves quite like I want it to (If it gets changed it also changes intB) The problem: I can't change references once they are set, right? Or is there a way? Everything in short: How do I get a value to work with * (pointers) and ** (pointers to pointers)?

    Read the article

  • Need advice about pointers and time elapsed program. How to fix invalid operands and cannot convert errors?

    - by user1781382
    I am trying to write a program that tells the difference between the two times the user inputs. I am not sure how to go about this. I get the errors : Line 27|error: invalid operands of types 'int' and 'const MyTime*' to binary 'operator-'| Line |39|error: cannot convert 'MyTime' to 'const MyTime*' for argument '1' to 'int DetermineElapsedTime(const MyTime*, const MyTime*)'| I also need a lot of help in this problem. I don't have a good curriculum, and my class textbook is like cliffnotes for programming. This will be my last class at this university. The C++ teztbook I use(my own not for class) is Sam's C++ One hour a day. #include <iostream> #include<cstdlib> #include<cstring> using namespace std; struct MyTime { int hours, minutes, seconds; }; int DetermineElapsedTime(const MyTime *t1, const MyTime *t2); long t1, t2; int DetermineElapsedTime(const MyTime *t1, const MyTime *t2) { return((int)t2-t1); } int main(void) { char delim1, delim2; MyTime tm, tm2; cout << "Input two formats for the time. Separate each with a space. Ex: hr:min:sec\n"; cin >> tm.hours >> delim1 >> tm.minutes >> delim2 >> tm.seconds; cin >> tm2.hours >> delim1 >> tm2.minutes >> delim2 >> tm2.seconds; DetermineElapsedTime(tm, tm2); return 0; } I have to fix the errors first. Anyone have any ideas??

    Read the article

  • How can pointers to functions point to something that doesn't exist in memory yet? Why do prototypes have different addresses?

    - by Kacy Raye
    To my knowledge, functions do not get added to the stack until run-time after they are called in the main function. So how can a pointer to a function have a function's memory address if it doesn't exist in memory? For example: using namespace std; #include <iostream> void func() { } int main() { void (*ptr)() = func; cout << reinterpret_cast<void*>(ptr) << endl; //prints 0x8048644 even though func never gets added to the stack } Also, this next question is a little less important to me, so if you only know the answer to my first question, then that is fine. But anyway, why does the value of the pointer ( the memory address of the function ) differ when I declare a function prototype and implement the function after main? In the first example, it printed out 0x8048644 no matter how many times I ran the program. In the next example, it printed out 0x8048680 no matter how many times I ran the program. For example: using namespace std; #include <iostream> void func(); int main() { void ( *ptr )() = func; cout << reinterpret_cast<void*>(ptr) << endl; } void func(){ }

    Read the article

  • Microsoft 2003 DNS sometimes cant query for some A pointers when their TTL expires

    - by Bq
    Warning Long question :) We have a win 2003 server with a DNS server, every now and then it cant provide us with some A pointers for a specific domain. I have a small script running which asks for SOA,NS and A records for the domain in question and sometimes when the TTL expires the DNS fails to get the A records again, a Clear Cache fixes the problem.. Have a look Here it worked when the TTL expired Thu Apr 29 15:24:20 METDST 2010 dig basefarm.net soa basefarm.net. 64908 IN SOA ns01.osl.basefarm.net. hostmaster.basefarm.net. 2010042613 86400 3600 2419200 600 ns01.osl.basefarm.net. 299 IN A 81.93.160.4 dig basefarm.net ns basefarm.net. 64908 IN NS ns01.sth.basefarm.net. basefarm.net. 64908 IN NS ns01.osl.basefarm.net. ns01.sth.basefarm.net. 299 IN A 80.76.149.76 ns01.osl.basefarm.net. 299 IN A 81.93.160.4 dig ns01.sth.basefarm.net a ns01.sth.basefarm.net. 299 IN A 80.76.149.76 The TTL expired for ns01.sth.basefarm.net and ns01.osl.basefarm.net but the DNS managed to get the new values (TTL 3600) Thu Apr 29 15:29:20 METDST 2010 dig basefarm.net soa basefarm.net. 64608 IN SOA ns01.osl.basefarm.net. hostmaster.basefarm.net. 2010042613 86400 3600 2419200 600 ns01.osl.basefarm.net. 3600 IN A 81.93.160.4 dig basefarm.net ns basefarm.net. 64608 IN NS ns01.sth.basefarm.net. basefarm.net. 64608 IN NS ns01.osl.basefarm.net. ns01.sth.basefarm.net. 3600 IN A 80.76.149.76 ns01.osl.basefarm.net. 3600 IN A 81.93.160.4 dig ns01.sth.basefarm.net a ns01.sth.basefarm.net. 3600 IN A 80.76.149.76 But then another time it fails, and we need to clear the dns cache for it to start working again... Thu Apr 29 17:24:23 METDST 2010 dig basefarm.net soa basefarm.net. 57705 IN SOA ns01.osl.basefarm.net. hostmaster.basefarm.net. 2010042613 86400 3600 2419200 600 ns01.osl.basefarm.net. 299 IN A 81.93.160.4 dig basefarm.net ns basefarm.net. 57705 IN NS ns01.sth.basefarm.net. basefarm.net. 57705 IN NS ns01.osl.basefarm.net. ns01.sth.basefarm.net. 299 IN A 80.76.149.76 ns01.osl.basefarm.net. 299 IN A 81.93.160.4 dig ns01.sth.basefarm.net a ns01.sth.basefarm.net. 299 IN A 80.76.149.76 The TTL expires but the DNS cant get the ip addresses for ns01.sth.basefarm.net and ns01.osl.basefarm.net Thu Apr 29 17:29:23 METDST 2010 dig basefarm.net soa basefarm.net. 57405 IN SOA ns01.osl.basefarm.net. hostmaster.basefarm.net. 2010042613 86400 3600 2419200 600 ns01.osl.basefarm.net. 3600 IN A 81.93.160.4 dig basefarm.net ns basefarm.net. 57405 IN NS ns01.sth.basefarm.net. basefarm.net. 57405 IN NS ns01.osl.basefarm.net. dig ns01.sth.basefarm.net a Lookup failed I'm really lost on this one and have tried asking Google but to no avail..

    Read the article

  • Container of shared_ptr's but iterate with raw pointers

    - by Sean Lynch
    I have a class that holds a list containing boost::shared_ptrs to objects of another class. The class member functions that give access to the elemets in the list return raw pointers. For consistency I'd also like to be able to iterate with raw pointers instead of shared_ptrs. So when I dereference the list iterator, I'd like to get raw pointer, not a shared_ptr. I assume I need to write a custom iterator for this. Is this correct? If so can someone point me in the right direction - I've never done this before.

    Read the article

  • Are raw C++ pointers first class objects?

    - by Shailesh Kumar
    According to Wikipedia: An object is first-class when it: can be stored in variables and data structures can be passed as a parameter to a subroutine can be returned as the result of a subroutine can be constructed at runtime has intrinsic identity (independent of any given name) Somebody had once told me that raw pointers are not first class objects while smart pointers like std::auto_ptr are. But to me, a raw pointer (to an object or to a function) in C++ does seem to me to satisfy the conditions stated above to qualify as a first class object. Am I missing something?

    Read the article

  • C doubt regarding array of pointers please explain

    - by ramya
    why do we use static with array of pointers?what is the relation betwwen static and array of pointers??plz help.... for eg: main() { int a[]={1,2,3}; int *p[]={a,a+1,a+2}; ...... } this code shows illegal initialization.why?whereas the following code works main() { static int a[]={1,2,3}; static int *p[]={a,a+1,a+2}; ...... } please do clear my doubt as soon as possible....

    Read the article

  • database row/ record pointers

    - by David
    Hi I don't know the correct words for what I'm trying to find out about and as such having a hard time googling. I want to know whether its possible with databases (technology independent but would be interested to hear whether its possible with Oracle, MySQL and Postgres) to point to specific rows instead of executing my query again. So I might initially execute a query find some rows of interest and then wish to avoid searching for them again by having a list of pointers or some other metadata which indicates the location on a database which I can go to straight away the next time I want those results. I realise there is caching on databases, but I want to keep these "pointers" else where and as such caching doesn't ultimately solve this problem. Is this just an index and I store the index and look up by this? most of my current tables don't have indexes and I don't want the speed decrease that sometimes comes with indexes. So whats the magic term I've been trying to put into google? Cheers

    Read the article

< Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >