How do i read a file into a variable?

[iwuvc]

I have a text file called s1.txt, and it has one value of 12345. Can somebody post an example of how to read this file into a variable? My tries have been pointless, I can't get fopen to work for my purpose.

 

[cpjust]

const size_t BUF_SIZE = 1024;
FILE* pFileIn = NULL;
char buf[ BUF_SIZE ];

if ( (pFileIn = fopen( "s1.txt", "rt" )) != NULL )
{
   if ( fgets( buf, BUF_SIZE, pFileIn ) != NULL )
   {
      /* Do something with your string. */
   }
   else
   {
      /* Error reading string. */
   }

   fclose( pFileIn );
}
else
{
   /* Error opening file. */
}