Date: Sun, 16 Apr 1995 18:59:52 -0500 (CDT) From: Peter da Silva <peter@bonkers.taronga.com> To: rpt@miles.sso.loral.com (Richard Toren) Cc: hackers@FreeBSD.org Subject: Re: aspfilter & stdin Message-ID: <199504162359.SAA02555@bonkers.taronga.com> In-Reply-To: <Pine.SUN.3.91.950416174558.11362A-100000@miles> from "Richard Toren" at Apr 16, 95 05:54:29 pm
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> I have modified the 'rewindstdin.c' as:
> #include <stdio.h>
> #include <unistd.h>
> main()
> {
> return lseek(0,0L,SEEK_SET) < 0;
> }
> Giving the following results:
> <src/rewind-stdin># make
> cc -s -O -o rewindstdin rewindstdin.c
> <src/rewind-stdin># cat rewindstdin.c | (file -; ./rewindstdin ;file -)
> standard input: c program text
> standard input: empty
You can't rewind a pipe.
Period.
Try "(file - ; ./rewindstdin ; file -) < rewindstdin.c".
> ?? why the '< 0' of the return code??
RETURN VALUES
Upon successful completion, lseek() returns the resulting offset location
as measured in bytes from the beginning of the file. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
It should be "return lseek(0,0L,SEEK_SET) == -1;"
I don't believe that any other nonzero result is possible in this case, but
it's always better to check for the documented return value.
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