Library to write an odf file from a C program
Does anyone know of a library that will allow me to write an odt (Open Document Format, i.e. OpenOffice compatible) file from a C program? ...
c
Porting Java app to Go - any advice?
We want to rewrite kodingen.com backend with Go which currently is Java, running as daemon using jsvc. I have never touched any C in my life, am only experienced in Java so I don't know if this is something that I should even start. However, task is pretty simple read shell commands from mysql database queue and execute them in paral...
How to get number of cores in C?
I'm writing a program in C on windows that needs to run as many threads as available cores. But I dont know how to get the number of cores. Any ideas? ...
How can I return to a string address and then assign it to a new string?
I have 1 function that I want to return the address of an assigned string to the main function and assign an new string pointer with the same address so that the new string will have the contents of the old string. For example: unknown_datatype function() { char *old = "THE STRING"; return old; } int main() { ch...
Lots of questions about file I/O (reading/writing message strings)
Hi, For this university project I'm doing (for which I've made a couple of posts in the past), which is some sort of social network, it's required the ability for the users to exchange messages. At first, I designed my data structures to hold ALL messages in a linked list, limiting the message size to 256 chars. However, I think my ins...
How to return a single variable from a CUDA kernel function?
I have a CUDA search function which calculate one single variable. How can I return it back. global void G_SearchByNameID(node* Node, long nodeCount, long start,char* dest, long answer){ answer = 2; } cudaMemcpy(h_answer, d_answer, sizeof(long), cudaMemcpyDeviceToHost); cudaFree(d_answer); for both of these lines I get this error...
Does the order I declare pointers really matter in C? getcwd() problem...
On a Solaris 5.8 machine, I have the following code: [non-working code] char *buf; char *dir; size_t psize; psize = (size_t) 1024; dir = getcwd(buf, psize); On this unix machine, the above does not work and I get a segmentation fault when trying to run the program. It only works if I declare dir before buf: [working code] char *d...
Can I make ungetc unblock a blocking fgetc call?
I would like to stuff an 'A' character back into stdin using ungetc on receipt of SIGUSR1. Imagine that I have a good reason for doing this. When calling foo(), the blocking read in stdin is not interrupted by the ungetc call on receipt of the signal. While I didn't expect this to work as is, I wonder if there is a way to achieve this...
WinMain not called before main (C/C++ Program Entry Point Issue)
I was under the impression that this code #include <windows.h> #include <stdio.h> int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { printf("WinMain\n"); return 0; } int main() { printf("main\n"); return 0; } would output WinMain, but of course nothing ever works how ...
C - how do i return multiple values from a function?
if i have a function that produces a result int and a result string how do i return them both from a function? as far as i can tell i can only return 1 thing, as determined by the type preceding the function name ...
Find function call in a list of binaries
I have a List of executables which may call a certain function. I need to find out which all execs call that function. I know I can do "strings -a " but is there some other better way to find that out. Full code is written in C. ...
How to use pthread_atfork() and pthread_once() to reinitialize mutexes in child processes
We have a C++ shared library that uses ZeroC's Ice library for RPC and unless we shut down Ice's runtime, we've observed child processes hanging on random mutexes. The Ice runtime starts threads, has many internal mutexes and keeps open file descriptors to servers. Additionally, we have a few of mutexes of our own to protect our intern...
Getting HWND of current Process
I have a process in c++ in which I am using window API. I want to get the HWND of own process. Kindly guide me how can I make it possible. ...
How to ANSI-C cast from unsigned int * to char *?
I want these two print functions to do the same thing: unsigned int Arraye[] = {0xffff,0xefef,65,66,67,68,69,0}; char Arrage[] = {0xffff,0xefef,65,66,67,68,69,0}; printf("%s", (char*)(2+ Arraye)); printf("%s", (char*)(2+ Arrage)); where Array is an unsigned int. Normally, I would change the type but, the proble...
Segmentation fault in a function to reverse a singly linked list recursivley.
I am implementing a function to recursively reverse a linked-list, but getting seg-fault. typedef struct _node { int data; struct _node *next; } Node, *NodeP; NodeP recursiveReverseList(NodeP first){ if(first == NULL) return NULL; if(first->next == NULL) return first; NodeP rest = recursiveReverseList(first->next); r...
Void pointers in C
I have written this qsort: void qsort(void *a[],int low,int high, int (*compare)(void*,void*)); When I call this on char *strarr[5]; It says invalid conversion from char** to void**. Why this is wrong? This is the code: #include<cstdlib> #include<cstdio> #include<iostream> using namespace std; inline void strswap(void *a,void *...
sort array of size n
if an array of size n has only 3 values 0 ,1 and 2 (repeated any number of times) what is the best way to sort them. best indicates complexity. consider space and time complexity both ...
Is it possible to have a variadic function in C with no non-variadic parameter?
I have the following function: void doStuff(int unusedParameter, ...) { va_list params; va_start(params, unusedParameter); /* ... */ va_end(params); } As part of a refactor, I'd like to remove the unused parameter without otherwise changing the implementation of the function. As far as I can tell, it's impossible to us...
What is the standard way to parse floats at runtime in C?
Hello, I have a scientific application for which I want to input initial values at runtime. I have an option to get them from the command line, or to get them from an input file. Either of these options are input to a generic parser that uses strtod to return a linked list of initial values for each simulation run. I either use the co...
How do I overwrite X bytes on offset Y with fwrite()?
Hi, All I can find using fopen() and fwrite() in C is to delete all contents and start writing again or append to the end of the file. What if I need to go to some offset in the file and overwrite a few bytes? Is that possible with some function? ...