Thread: Piping problem

I get garbage output when printing the string s.
This is after obtaining the output from xrandr -q, which will list monitor devices and resolutions.
I use this to determine if VGA1 has diconnected, and if so turn on display LVDS1 and exit the program.

If you can tell me why s contains garbage i would be grateful.

Code:

#include <string.h>
#include <stdio.h>
//Searches a string for string in var 'me', returns the starting position of the found string +1 if successfull.
//On failure it returns 0.
unsigned int str_find(const char*str, const char* me, unsigned int s){
        
        unsigned int x = 0, l = strlen(me) - 1;
        while( (str[s] ^ '\0') ){
            if ( !(str[s]^me[x]) ){
                //cout<<"Equal at " << s << ',' << x << endl;
                if ( !(x^l) )
                    return s - x + 1;
                    
                if ( (str[s+1]^me[x+1]) )
                    s -= x-2, x = 0;
                else ++x;
            }
            ++s;
        } 
        return 0;
}


int main(){
  
  FILE *f;
  int c;
  unsigned short n;
  char s[1024];
  while( (f=popen("xrandr -q", "r")) ){
    
    for( n = 0; (c=fgetc(f) != EOF ); ++n )
      s[n] = c;
    s[n] = '\0';


    pclose(f);
    
    printf("%s",s);
    
    if( str_find("VGA1 disconnected", s, 0) > 0 ){
      printf("VGA1 Disconnected, igniting LVDS1 and exiting program\n");
      system("xrandr --output LVDS1 --auto");
      return 0;
      }
      
  }
  
  return 1;
}

Thank you, and sorry about the ^'s.