Programming

#include <stdlib.h>
#include <stdio.h>
int main(int argc, char **argv)
{
   if(argc > 1)
   { 
      char tmp[256]={0x0};
      FILE *in=fopen(argv[1], "r");
      if(in==NULL)
      {
           perror("Error opening input file")
           exit(1);
      }
      while (fgets(tmp, sizeof(tmp), in)!=NULL) printf("%s", tmp);
      if(feof(in) )
      {
               fclose(in);
               return 0;
       }    
       perror("File I/O error");
   }
   return 1;
}