question on lseek behavior

[Eric Marshall]

	I was trying to use lseek to rewind to the beginning
of input (a file), but I ran into difficulties.  When I run
the program below, it outputs the file missing the first 3 characters,
as if the lseek didn't do anything, then it outputs the entire
file.  Could someone please explain why this occurs.  I eventually
found the rewind(3S) call, and it works fine.  I am running
on SunOS 4.1.

	Thanks in advance.

	seek_test.c:

		#include <stdio.h>
		#include <sys/types.h>
		#include <sys/file.h>
		
		main()
		{
		  int c;
		  FILE *infile = fopen( "seek_test.c", "r" );
		
		  c = getc( infile );
		  c = getc( infile );
		  c = getc( infile );
		
		  lseek( fileno( infile ), 0L, L_SET );
		
		  while ( ( c = getc( infile ) ) != EOF ) putchar( c );
		}


Eric Marshall
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