C: Run a System Command and Get Output?

c linux system
jimi hendrix picture jimi hendrix · Mar 14, 2009 · Viewed 260k times · Source

Possible Duplicate:
How can I run an external program from C and parse its output?

I want to run a command in linux and get the text returned of what it outputs, but I do not want this text printed to screen. Is there a more elegant way than making a temporary file?

Answer

user14038 picture user14038 · Mar 14, 2009

You want the "popen" function. Here's an example of running the command "ls /etc" and outputing to the console.

#include <stdio.h>
#include <stdlib.h>


int main( int argc, char *argv[] )
{

  FILE *fp;
  char path[1035];

  /* Open the command for reading. */
  fp = popen("/bin/ls /etc/", "r");
  if (fp == NULL) {
    printf("Failed to run command\n" );
    exit(1);
  }

  /* Read the output a line at a time - output it. */
  while (fgets(path, sizeof(path), fp) != NULL) {
    printf("%s", path);
  }

  /* close */
  pclose(fp);

  return 0;
}

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