Replace C instructions for system calls Post: 302944306

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Top Forums Shell Programming and Scripting Replace C instructions for system calls Post 302944306 by alwayslearn on Monday 18th of May 2015 05:09:45 PM

05-18-2015

Registered User

Replace C instructions for system calls

Hi!

At first I'm new to this forum and I'm not sure if this post is correct in this place.

I have a problem trying to change 2 C instructions for system calls. The code that I have is that:

Code:

#include <stdlib.h> 
#include <stdio.h> 
#include <string.h> 
#include <errno.h> 
#include <unistd.h> 
 
#include "rutines.h" 
 
int main(int argc, char *argv[]) 
{ 
    char cmd[256]; 
    int a; 
     
    if (argc<2) 
        Error("Insufficient arguments: exec_in <sec> <cmd> [args...]"); 
         
    sleep(atoi(argv[1])); 
     
    cmd[0]='\0'; 
    for(a=2;a<argc;a++) 
    { 
        strcat(cmd,argv[a]); 
        strcat(cmd," "); 
    } 
     
    system(cmd); 
         
    exit(0); 
}

I need to change the instructions sleep and system for some system calls (I use Ubuntu 12.04 64bits). I have only been using linux one week and I'm really lost. I never used system calls in C before. Someone can help me?

Thanks!

PS: sorry, I've some errors in the code that I posted, I corrected it.

Last edited by alwayslearn; 05-19-2015 at 04:56 AM..

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