FILE Pointer (stream)
 shows on a given file
 // here is a better explanation necessary

#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */
 
 
int main ( void )
{
FILE *filestream;
 
filestream=fopen("test.txt","r");
 
if (filestream == 0) {
perror("cannot open file");
}
 
fclose(filestream);
return 0;
 
}