#include <stdio.h>
  int putc( int ch, FILE *stream );

The putc() function writes the character ch to stream. The return value is the character written, or EOF if there is an error. For example:

   int ch;
   FILE *input, *output;
   input = fopen( "tmp.c", "r" );
   output = fopen( "tmpCopy.c", "w" );
   ch = getc( input );
   while( ch != EOF ) {
     putc( ch, output );
     ch = getc( input );
   }
   fclose( input );
   fclose( output );            

generates a copy of the file tmp.c called tmpCopy.c.