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  • C# textbox cursor positioning

    - by Jim
    I feel like I am just missing a simple property, but can you set the cursor to the end of a line in a textbox? private void txtNumbersOnly_KeyPress(object sender, KeyPressEventArgs e) { if (Char.IsDigit(e.KeyChar) || e.KeyChar == '\b' || e.KeyChar == '.' || e.KeyChar == '-') { TextBox t = (TextBox)sender; bool bHandled = false; _sCurrentTemp += e.KeyChar; if (_sCurrentTemp.Length > 0 && e.KeyChar == '-') { // '-' only allowed as first char bHandled = true; } if (_sCurrentTemp.StartsWith(Convert.ToString('.'))) { // add '0' in front of decimal point t.Text = string.Empty; t.Text = '0' + _sCurrentTemp; _sCurrentTemp = t.Text; bHandled = true; } e.Handled = bHandled; } After testing for '.' as first char, the cursor goes before the text that is added. So instead of "0.123", the results are "1230." without moving the cursor myself. I also apologize if this is a duplicate question.

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  • glibc detected ./.a.out: free(): invalid pointer

    - by ExtremeBlue
    typedef struct _PERSON { size_t age; unsigned char* name; }PERSON; int init(PERSON** person) { (* person) = (PERSON *) malloc(sizeof(struct _PERSON)); (* person)->age = 1; (* person)->name = (unsigned char *) malloc(sizeof(4)); (* person)->name = "NAME"; return 0; } void close(PERSON** person) { (* person)->age = 0; if((* person)->name != NULL) { free((* person)->name); } if((* person) != NULL) { free((* person)); } } int main(int argc, char* argv[]) { PERSON* p; init(&p); printf("%d\t%s\n", (int) p->age, p->name); close(&p); return 0; } 1 NAME *** glibc detected *** ./a.out: free(): invalid pointer: 0x000000000040079c *** ======= Backtrace: ========= /lib/libc.so.6(+0x774b6)[0x7fa9027054b6] /lib/libc.so.6(cfree+0x73)[0x7fa90270bc83] ./a.out(close+0x3d)[0x400651] ./a.out[0x40069f] /lib/libc.so.6(__libc_start_main+0xfe)[0x7fa9026acd8e] ./a.out[0x4004f9] ... 7fa8fc000000-7fa8fc021000 rw-p 00000000 00:00 0 7fa8fc021000-7fa900000000 ---p 00000000 00:00 0 7fa902478000-7fa90248d000 r-xp 00000000 08:12 23068732 /lib/libgcc_s.so.1 7fa90248d000-7fa90268c000 ---p 00015000 08:12 23068732 /lib/libgcc_s.so.1 7fa90268c000-7fa90268d000 r--p 00014000 08:12 23068732 /lib/libgcc_s.so.1 7fa90268d000-7fa90268e000 rw-p 00015000 08:12 23068732 /lib/libgcc_s.so.1 7fa90268e000-7fa902808000 r-xp 00000000 08:12 23068970 /lib/libc-2.12.1.so 7fa902808000-7fa902a07000 ---p 0017a000 08:12 23068970 /lib/libc-2.12.1.so 7fa902a07000-7fa902a0b000 r--p 00179000 08:12 23068970 /lib/libc-2.12.1.so 7fa902a0b000-7fa902a0c000 rw-p 0017d000 08:12 23068970 /lib/libc-2.12.1.so 7fa902a0c000-7fa902a11000 rw-p 00000000 00:00 0 7fa902a11000-7fa902a31000 r-xp 00000000 08:12 23068966 /lib/ld-2.12.1.so 7fa902c25000-7fa902c28000 rw-p 00000000 00:00 0 7fa902c2e000-7fa902c31000 rw-p 00000000 00:00 0 7fa902c31000-7fa902c32000 r--p 00020000 08:12 23068966 /lib/ld-2.12.1.so 7fa902c32000-7fa902c33000 rw-p 00021000 08:12 23068966 /lib/ld-2.12.1.so 7fa902c33000-7fa902c34000 rw-p 00000000 00:00 0 7fff442d5000-7fff442f6000 rw-p 00000000 00:00 0 [stack] 7fff44308000-7fff44309000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Aborted

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  • Simulation tree command in C

    - by Ecle
    I have to create the simulation of tree command in C, this is my current code: #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <dirent.h> #include <string.h> main(int argc, char *argv[]){ int i; if(argc < 2){ printf("\nError. Use: %s directory\n", argv[0]); system("exit"); } for(i=1;i<argc;i++) //if(argv[i][0] != '-') tree(argv[i]); } tree(char *ruta){ DIR *dirp; struct dirent *dp; static nivel = 0; struct stat buf; char fichero[256]; int i; if((dirp = opendir(path)) == NULL){ perror(path); return; } while((dp = readdir(dirp)) != NULL){ printf(fichero, "%s/%s", path, dp->d_name); if((buf.st_mode & S_IFMT) == S_IFDIR){ for(i=0;i<nivel;i++) printf("\t"); printf("%s\n", dp->d_name); ++nivel; tree(fichero); --nivel; } } } Apparently, it works! (due to it compiles correctly) But I don't why. I can't pass the correct arguments to execute this. Thank you so much, people.

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  • C++, array declaration, templates, linker error

    - by justik
    There is a linker error in my SW. I am using the following structure based on h, hpp, cpp files. Some classes are templatized, some not, some have function templates. Declaration: test.h #ifndef TEST_H #define TEST_H class Test { public: template <typename T> void foo1(); void foo2 () }; #include "test.hpp" #endif Definition: test.hpp #ifndef TEST_HPP #define TEST_HPP template <typename T> void Test::foo1() {} inline void Test::foo2() {} //or in cpp file #endif CPP file: test.cpp #include "test.h" void Test::foo2() {} //or in hpp file as inline I have the following problem. The variable vars[] is declared in my h file test.h #ifndef TEST_H #define TEST_H char *vars[] = { "first", "second"...}; class Test { public: void foo(); }; #include "test.hpp" #endif and used as a local variable inside foo() method defined in hpp file as inline. test.hpp #ifndef TEST_HPP #define TEST_HPP inline void Test::foo() { char *var = vars[0]; //A Linker Error } #endif However, the following linker error occurs: Error 745 error LNK2005: "char * * vars" (?vars@@3PAPADA) already defined in test2.obj How and where to declare vars[] to avoid linker errors? After including #include "test.hpp" it is late to declare it...

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  • Pointer and malloc issue

    - by Andy
    I am fairly new to C and am getting stuck with arrays and pointers when they refer to strings. I can ask for input of 2 numbers (ints) and then return the one I want (first number or second number) without any issues. But when I request names and try to return them, the program crashes after I enter the first name and not sure why. In theory I am looking to reserve memory for the first name, and then expand it to include a second name. Can anyone explain why this breaks? Thanks! #include <stdio.h> #include <stdlib.h> void main () { int NumItems = 0; NumItems += 1; char* NameList = malloc(sizeof(char[10])*NumItems); printf("Please enter name #1: \n"); scanf("%9s", NameList[0]); fpurge(stdin); NumItems += 1; NameList = realloc(NameList,sizeof(char[10])*NumItems); printf("Please enter name #2: \n"); scanf("%9s", NameList[1]); fpurge(stdin); printf("The first name is: %s",NameList[0]); printf("The second name is: %s",NameList[1]); return 0; }

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  • c++ push_back doesn't work as it is supposed

    - by angela
    I have a class symbol_table that has a vector of objects of another class row_st.also I have an enter method where inserts objects of row_st with a passed name into the vector of desired symbol_table.but when I call the enter to enter objects with name : a;b;c;Iwill get the following result: a,b,c;b,c;c.the first element of vector gets the name of all the entered objects. and the second element also gets the name of the later entries. class row_st { public: char* name; type_u type;//int:0,flaot:1;char:2,bool:3,array: int offset; symbol_table *next; symbol_table *current; }; class symbol_table { public: vector <row_st *> row; int type; int header; int starting_stmt; int index; int i; symbol_table *previous; symbol_table(){ header=0; previous=0; index=0;i=0;starting_stmt=0;} }; and here it is the enter method: int enter(symbol_table *table,char* name,type_u type){ row_st *t=new row_st; t->name=name; t->type=type; t->offset=table->index; t->current=table; table->index++; t->next=0; table->row.push_back(t); table->header +=1; return table->row.size()-1; } the push_backed elements all points to the same address.the new call makes the same row_st every time it is called.what should I do?

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  • How to determine 2D unsigned short pointers array length in c++

    - by tuman
    Hello, I am finding it difficult to determine the length of the columns in a 2D unsigned short pointer array. I have done memory allocation correctly as far as I know. and can print them correctly. plz see the following code segment: int number_of_array_index_required_for_pointer_abc=3; char A[3][16]; strcpy(A[0],"Hello"); strcpy(A[1],"World"); strcpy(A[2],"Tumanicko"); cout<<number_of_array_index_required_for_pointer_abc*sizeof(unsigned short)<<endl; unsigned short ** pqr=(unsigned short **)malloc(number_of_array_index_required_for_pointer_abc*sizeof(unsigned short)); for(int i=0;i<number_of_array_index_required_for_pointer_abc;i++) { int ajira = strlen(A[i])*sizeof(unsigned short); cout<<i<<" = "<<ajira<<endl; pqr[i]=(unsigned short *)malloc(ajira); cout<<"alocated pqr[i]= "<<sizeof pqr<<endl; int j=0; for(j=0;j<strlen(A[i]);j++) { pqr[i][j]=(unsigned short)A[i][j]; } pqr[i][j]='\0'; } for(int i=0;i<number_of_array_index_required_for_pointer_abc;i++) { //ln= (sizeof pqr[i])/(sizeof pqr[0]); //cout<<"Size of pqr["<<i<<"]= "<<ln<<endl; // I want to know the size of the columns i.e. pqr[i]'s length instead of finding '\0' for(int k=0;(char)pqr[i][k]!='\0';k++) cout<<(char)pqr[i][k]; cout<<endl; }

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  • Make conversion to a native type explicit in C++

    - by Tal Pressman
    I'm trying to write a class that implements 64-bit ints for a compiler that doesn't support long long, to be used in existing code. Basically, I should be able to have a typedef somewhere that selects whether I want to use long long or my class, and everything else should compile and work. So, I obviously need conversion constructors from int, long, etc., and the respective conversion operators (casts) to those types. This seems to cause errors with arithmetic operators. With native types, the compiler "knows" that when operator*(int, char) is called, it should promote the char to int and call operator*(int, int) (rather than casting the int to char, for example). In my case it gets confused between the various built-in operators and the ones I created. It seems to me like if I could flag the conversion operators as explicit somehow, that it would solve the issue, but as far as I can tell the explicit keyword is only for constructors (and I can't make constructors for built-in types). So is there any way of marking the casts as explicit? Or am I barking up the wrong tree here and there's another way of solving this? Or maybe I'm just doing something else wrong...

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  • Another boost error

    - by user1676605
    On this code I get the enourmous error static void ParseTheCommandLine(int argc, char *argv[]) { int count; int seqNumber; namespace po = boost::program_options; std::string appName = boost::filesystem::basename(argv[0]); po::options_description desc("Generic options"); desc.add_options() ("version,v", "print version string") ("help", "produce help message") ("sequence-number", po::value<int>(&seqNumber)->default_value(0), "sequence number") ("pem-file", po::value< vector<string> >(), "pem file") ; po::positional_options_description p; p.add("pem-file", -1); po::variables_map vm; po::store(po::command_line_parser(argc, argv). options(desc).positional(p).run(), vm); po::notify(vm); if (vm.count("pem file")) { cout << "Pem files are: " << vm["pem-file"].as< vector<string> >() << "\n"; } cout << "Sequence number is " << seqNumber << "\n"; exit(1); ../../../FIXMarketDataCommandLineParameters/FIXMarketDataCommandLineParameters.hpp|98|error: no match for ‘operator<<’ in ‘std::operator<< [with _Traits = std::char_traits](((std::basic_ostream &)(& std::cout)), ((const char*)"Pem files are: ")) << ((const boost::program_options::variable_value*)vm.boost::program_options::variables_map::operator[](((const std::string&)(& std::basic_string, std::allocator (((const char*)"pem-file"), ((const std::allocator&)((const std::allocator*)(& std::allocator()))))))))-boost::program_options::variable_value::as with T = std::vector, std::allocator , std::allocator, std::allocator ’|

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  • Extracting exported functions out of a shared lib (ubuntu)

    - by Pingu
    the title already describes my problem. I found this post, but it didn't completely answers my question. With the help of it i got this output from nm... $nm -C -g -D ./libLoggingHandler.so 000000cc A _DYNAMIC ... 000042e0 T write_str(char*, char const*, int*) 00005a78 T RingBuffer::WriteUnlock() ... 00005918 T TraceLines::GetItemSize() ... U SharedMemory::attach(int, void const*, int) ... 00003810 T TraceProfile::FindLineNr(int, int) ... 00002d40 T LoggingHandler::getLogLevel() ... U SharedResource::getSharedResourceKey(char const*, int) ... which are the exported functions? I already found a hint in this post, that the "T" indicates that its getting exported. But if i check the nm manual here, it just says T - The symbol is in the text (code) section. My questions is: Does this output give me the information which functions are exported functions (or variables)? If not, how do i get it? Greetings, Pingu

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  • Need some help understanding a weird C behavior

    - by mike
    This part of my code works fine: #include <stdio.h> int main(){ //char somestring[3] = "abc"; int i, j; int count = 5; for((i=0) && (j=0); count > 0; i++ && j++){ printf("i = %d and j = %d\n", i, j); count--; } return 0; } The output as expected: i : 0 and j : 0 i : 1 and j : 1 i : 2 and j : 2 i : 3 and j : 3 i : 4 and j : 4 Things get weird when I uncomment the char string declaration on the first line of the function body. #include <stdio.h> int main(){ char somestring[3] = "abc"; ... } The output: i : 0 and j : 4195392 i : 1 and j : 4195393 i : 2 and j : 4195394 i : 3 and j : 4195395 i : 4 and j : 4195396 What's the logic behind this? I'm using gcc 4.4.1 on Ubuntu 9.10.

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  • [gtk+] run function in another thread than gui

    - by sterh
    Hello, I have simple C/gtk+ application. I have function in this app which load image in gtkimageview widget: gboolean main_win_open( MainWin* mw, const char* file_path) { ... //loading and displaing image in gtkimageview ... } The loading image is work, but i need to run this function in another thread then main gui form; I have function: void* argument_thread(void *args) { Data *data = (Data*)args; gdk_threads_enter(); main_win_open (data->win,data->argv); gdk_threads_leave(); } Data it's structure for main_win_open function arguments: typedef struct _Data { MainWin *win; char* argv; } Data; Then in main function i create thread and run it: int main(int argc, char** argv) { GError* err; GThread* thread; Data data; MainWin *win; // init thread support if(!g_thread_supported()) g_thread_init(NULL); gdk_threads_init(); // init GTK+ gtk_init (&argc, &argv); win = (MainWin*)main_win_new(); gtk_widget_show(GTK_WIDGET(win)); data.win = win; data.argv = argv[1]; if (argc == 2) { thread = g_thread_create((GThreadFunc)argument_thread,&data,FALSE, &err); } gdk_threads_enter(); gtk_main(); gdk_threads_leave(); } But when i try to run app from command line and try to load big-size image, gui is blocking. What's wrong? Thank you.

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  • VB 2008 - Index was outside the bounds of the array

    - by Jan
    Hey guys I'm having a problem while reading a config.cfg file of my program. I can read the 23. char of the file but I can't read the 24. char (last char in file). This is the code: Dim CFGReader2 As System.IO.StreamReader CFGReader2 = _ My.Computer.FileSystem.OpenTextFileReader(CurDir() & "\Config.cfg") Dim Server(2) As String Server(0) = CFGReader2.ReadToEnd.Chars(23)//This part works If Server(0) = 0 Then Server(1) = CFGReader2.ReadToEnd.Chars(24)//This part results in "Index was outside the bounds of the array". ElseIf Server(0) = 1 Then Server(2) = CFGReader2.ReadToEnd.Chars(24)//This part results in "Index was outside the bounds of the array". Server(1) = 10 + Server(2) ElseIf Server(0) = 2 Then Server(2) = CFGReader2.ReadToEnd.Chars(24)//This part results in "Index was outside the bounds of the array". Server(1) = 20 + Server(2) ElseIf Server(0) = 3 Then Server(2) = CFGReader2.ReadToEnd.Chars(24)//This part results in "Index was outside the bounds of the array". Server(1) = 30 + Server(2) End If And this is the file: Language = 2 Server = 11 Thanks for the answer! Frosty

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  • Crash in C++ Code

    - by Ankuj
    I am trying to list all files in a directory recursively. But my code crashes without giving any error. When the given file is directory I recursively call the function or else print its name. I am using dirent.h int list_file(string path) { DIR *dir; struct dirent *ent; char *c_style_path; c_style_path = new char[path.length()]; c_style_path = (char *)path.c_str(); dir = opendir (c_style_path); if (dir != NULL) { /* print all the files and directories within directory */ while ((ent = readdir (dir)) != NULL) { if(ent->d_type == DT_DIR && (strcmp(ent->d_name,".")!=0) && (strcmp(ent->d_name,"..")!=0)) { string tmp = path + "\\" + ent->d_name; list_file(tmp); } else { cout<<ent->d_name<<endl; } } closedir (dir); } else { /* could not open directory */ perror (""); return EXIT_FAILURE; } delete [] c_style_path; return 0; } I am not getting as to what I am doing wrong here. Any clues ?

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  • Using unions to simplify casts

    - by Steven Lu
    I realize that what I am trying to do isn't safe. But I am just doing some testing and image processing so my focus here is on speed. Right now this code gives me the corresponding bytes for a 32-bit pixel value type. struct Pixel { unsigned char b,g,r,a; }; I wanted to check if I have a pixel that is under a certain value (e.g. r, g, b <= 0x10). I figured I wanted to just conditional-test the bit-and of the bits of the pixel with 0x00E0E0E0 (I could have wrong endianness here) to get the dark pixels. Rather than using this ugly mess (*((uint32_t*)&pixel)) to get the 32-bit unsigned int value, i figured there should be a way for me to set it up so I can just use pixel.i, while keeping the ability to reference the green byte using pixel.g. Can I do this? This won't work: struct Pixel { unsigned char b,g,r,a; }; union Pixel_u { Pixel p; uint32_t bits; }; I would need to edit my existing code to say pixel.p.g to get the green color byte. Same happens if I do this: union Pixel { unsigned char c[4]; uint32_t bits; }; This would work too but I still need to change everything to index into c, which is a bit ugly but I can make it work with a macro if i really needed to.

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  • How to delay execution of a method in c#?

    - by Pandiya Chendur
    I have this if condition, if (sendSMS(Convert.ToInt32(DLComportNo.SelectedItem.Text), TxtDriMob.Text, TxtCliDet.Text) && sendSMS(Convert.ToInt32(DLComportNo.SelectedItem.Text), TxtCliMob.Text, TxtDriDet.Text)) { // I am inserting details to my db } and my sendSMS method looks like this, private bool sendSMS(int portNo, string mobNo, string details) { try { SerialPort SerialPort1 = new SerialPort(); SerialPort1.PortName = "COM" + portNo.ToString(); SerialPort1.BaudRate = 9600; SerialPort1.Parity = Parity.None; SerialPort1.DataBits = 8; SerialPort1.StopBits = StopBits.One; SerialPort1.RtsEnable = true; SerialPort1.DtrEnable = true; SerialPort1.Encoding.GetEncoder(); SerialPort1.ReceivedBytesThreshold = 1; SerialPort1.NewLine = Environment.NewLine; SerialPort1.Open(); SerialPort1.Write("AT" + SerialPort1.NewLine); Sleep(500); SerialPort1.Write("AT+CMGF=1" + SerialPort1.NewLine); Sleep(500); SerialPort1.Write("AT+CMGS=" + (char)34 + mobNo + (char)34 + SerialPort1.NewLine); Sleep(1000); SerialPort1.Write(details + (char)26); Sleep(2000); SerialPort1.Close(); } catch { } return true; } What happens is when i use break point in my sendSMS i get my output (ie) both the methods get executed and messages are sent properly... But when i removed my breakpoint both the methods in the if statement are executed but message from the first method is sent and not from the second method.... Any suggestion?

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  • Can somebody please explain this recursive function for me?

    - by capncoolio
    #include <stdio.h> #include <stdlib.h> void reprint(char *a[]) { if(*a) { printf("%d ",a); reprint(a+1); printf("%s ",*a); } } int main() { char *coll[] = {"C", "Objective", "like", "don't", "I", NULL}; reprint(coll); printf("\n"); return EXIT_SUCCESS; } As the more experienced will know, this prints the array in reverse. I don't quite understand how! I need help understanding what reprint(char *a[]) does. I understand pointer arithmetic to a degree, but from inserting printf's here and there, I've determined that the function increments up to the array end, and then back down to the start, only printing on the way down. However, I do not understand how it does this; all I've managed to understand by looking at the actual code is that if *a isn't NULL, then call reprint again, at the next index. Thanks guys!

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  • sockaddr_in causing segfault?

    - by Curlystraw
    Working on creating a server/client system in C right now, and I'm having a little trouble with the client part. From what I've seen, I need to use sockaddr_in so I can connect to the server. However, I've been getting a segfault every time. I believe that sockaddr_in has something to do with it, as comment it and it's references later in the program fixes the segfault. code: #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <unistd.h> #include <netinet/in.h> int main(int argc, char** argv) { int Csock; int con; char *data = 0; char buf[101] = ""; struct sockaddr_in addr; Csock = socket(AF_INET, SOCK_STREAM, 0); addr.sin_family = AF_INET; addr.sin_port = htons(3435); con = connect(Csock, (struct sockaddr*) &addr, sizeof(&addr)); write(con, "Text", sizeof("Text")); *data = read(con, buf, 100); puts(data); return 0; } sadly, I am rather new to C, so that's as much as I can figure... can anyone tell me a way to go about eliminating the segfault? Thanks!

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  • Different output between release and Debug

    - by AthomSfere
    I can't figure this one out. I have a c++ Application that works in Debug mode exactly as expected: #include "stdafx.h" #include <string> #include <Windows.h> #include <iostream> using namespace std; void truncateServer(std::string inString); int _tmain(int argc, char *argv[]) { char* server = argv[1]; truncateServer(server); } void truncateServer(std::string inString) { std::string server = ""; int whackCount = 0; for (unsigned int i = 0; i < inString.length(); i++) { char c = inString[i]; if (whackCount < 3) { if (c == '\\') whackCount++; else server += c; } } cout << server; } For example if I call the server I want via its UNC path \\serverName\Share\ in the debug it gives me exactly what I want: servername However, if I use the release build I get nothing: I deleted the release output folder, but the issue is exactly the same. I can only assume there is some other difference between the release and build applications that is exposing a major issue with my code? Or another difference between the outputs I need to account for. What do I need to do to get the expected output?

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  • safe structures embedded systems

    - by user405633
    I have a packet from a server which is parsed in an embedded system. I need to parse it in a very efficient way, avoiding memory issues, like overlapping, corrupting my memory and others variables. The packet has this structure "String A:String B:String C". As example, here the packet received is compounded of three parts separated using a separator ":", all these parts must be accesibles from an structure. Which is the most efficient and safe way to do this. A.- Creating an structure with attributes (partA, PartB PartC) sized with a criteria based on avoid exceed this sized from the source of the packet, and attaching also an index with the length of each part in a way to avoid extracting garbage, this part length indicator could be less or equal to 300 (ie: part B). typedef struct parsedPacket_struct { char partA[2];int len_partA; char partB[300];int len_partB; char partC[2];int len_partC; }parsedPacket; The problem here is that I am wasting memory, because each structure should copy the packet content to each the structure, is there a way to only save the base address of each part and still using the len_partX.

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  • C++: getting the address of the start of an std::vector ?

    - by shoosh
    Sometimes it is useful to use the starting address of an std::vector and temporarily treat that address as the address of a regularly allocated buffer. For instance replace this: char* buf = new char[size]; fillTheBuffer(buf, size); useTheBuffer(buf, size); delete[] buf; With This: vector<char> buf(size); fillTheBuffer(&buf[0], size); useTheBuffer(&buf[0], size); The advantage of this is of course that the buffer is deallocated automatically and I don't have to worry about the delete[]. The problem I'm having with this is when size == 0. In that case the first version works ok. An empty buffer is "allocated" and the subsequent functions do nothing size they get size == 0. The second version however fails if size == 0 since calling buf[0] may rightly contain an assertion that 0 < size. So is there an alternative to the idiom &buf[0] that returns the address of the start of the vector even if the vector is empty? I've also considered using buf.begin() but according to the standard it isn't even guaranteed to return a pointer.

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  • What is the last entry in an unfilled array (C++)?

    - by jwaffe
    I put C++ because I'm just starting in C# and I'm not sure if there's a difference. if you declare an array char arr[10] and fill in values for arr[0] through arr[8], what value will be put in arr[9]? a space ' '? An endline '\n'? '\0'? Or is it nothing at all? I'm asking this because I've always used tactics like this char word[20]; for(count = 0 ; count < 20 ; count++) { cout << word[count]; } to print the entire contents of an array, and I was wondering if I could simplify it (e.g., if the last entry was '\0') by using something like this char word[20]; while(word[count] != '\0') { cout << word[count]; } that way, I wouldn't have to remember how many pieces of data were entered into an array if all the spaces weren't filled up. If you know an even faster way, let me know. I tend to make a bunch of mistakes on arrays.

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  • numbers aren't right when reading text file, have to tally up number of 5 letter words and 6 or more

    - by user320950
    i want to do this: reads the words in the file one at a time. (Use a string to do this) Counts three things: how many single-character words are in the file, how many short (2 to 5 characters) words are in the file, and how many long (6 or more characters) words are in the file. HELP HERE im not sure on how about reading file into a string. i know i have to something like this but i dont understand the rest. HELP HERE ifstream infile; //char mystring[6]; //char mystring[20]; int main() { infile.open("file.txt"); if(infile.fail()) { cout << " Error " << endl; } int numb_char=0; char letter; while(!infile.eof()) { infile.get(letter); cout << letter; numb_char++; break; } cout << " the number of characters is :" << numb_char << endl; infile.close(); return 0;

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  • Format a timestamp into text

    - by user1257114
    I want to get the Modify date of a file and then format it into a human readable date. I am running a C program that gets information on when a particular file was last modified. My C Code contains a sytem cmd which contains a number of egreps, awks, seds separated by pipes. Using sed or awk or something similar, how can I convert 06 to June (This can be any month so an array or something is required) What I am trying to achieve is to end up with a string similar to: My C code contains: char string1[100] = ""; #define MAXCHAR 100 FILE *fp; char str[MAXCHAR], str2[MAXCHAR]; char* filename = "newfile"; /* stat: run 'stat' on the dtlName file to display status information. egrep: search for the pattern 'Modify' and print the lines containing it. awk: Get columns 2 & 3 sed: replace the . with a space, leaving 3 columns of output awk: only print cols 1 & 2 to newfile sed: replace '-' with ' ' in newfile awk: format output in newfile */ sprintf(string1, "/bin/stat %s \ | egrep Modify \ | /bin/awk '{print $2, $3}' \ | /bin/sed 's/\\./ /g' \ | /bin/awk '{print $1, $2}' \ | /bin/sed 's/-/ /g' \ | /bin/awk '{print $3,$2\", \"$1,\"at\",$4}' > newfile" , dtlName); system(string1); fp = fopen(filename, "r"); while (fgets(str, MAXCHAR, fp) != NULL) sprintf(str2,"%s", str); /* Write information to file */ DisplayReportFile (report); ReportEntry (report,L"Source file: %s, Created: %s\n\n",dtlName,str2);

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  • Cannot determine why pointer variable will not address elements in a string in this program?

    - by Smith Will Suffice
    I am attempting to utilize a pointer variable to access elements of a string and there are issues with my code generating a compilation error: #include <stdio.h> #define MAX 29 char arrayI[250]; char *ptr; int main(void) { ptr = arrayI; puts("Enter string to arrayI: up to 29 chars:\n"); fgets(arrayI, MAX, stdin); printf("\n Now printing array by pointer:\n"); printf("%s", *ptr); ptr = arrayI[1]; //(I set the pointer to the second array char element) printf("%c", *ptr); //Here is where I was wanting to use my pointer to //point to individual array elements. return 0; } My compiler crieth: [Warning] assignment makes pointer from integer without a cast [enabled by default] I do not see where my pointer was ever assigned to the integer data type? Could someone please explain why my attempt to implement a pointer variable is failing? Thanks all!

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