#include <stdlib.h>  
#include <stdio.h>  
  
#define BUF_SIZE 1024  
char buf[BUF_SIZE];  
  
int main(void)  
{  
    FILE * p_file = NULL;  
  
    p_file = popen("cat /proc/version", "r");  
    if (!p_file) {  
        fprintf(stderr, "Erro to popen");  
    }  
  
    while (fgets(buf, BUF_SIZE, p_file) != NULL) {  
        fprintf(stdout, "%s", buf);  
    }  
    pclose(p_file);     
  
    return 0;  
}