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[ID 20000207.003] close for piped open sets $! to the wrong value

February 7, 2000 10:46
[ID 20000207.003] close for piped open sets $! to the wrong value
Message ID:
This is a bug report for perl from,
generated with the help of perlbug 1.26 running under perl 5.00503.

[Please enter your report here]

This program runs /bin/false, a standard unix command, on a piped
open, then closes the filehandle.  /bin/false is the program which
exits immediately with exit status 1.  According to the manual: 

        If the file handle came from a piped open C<close()> will
        additionally return FALSE if one of the other system calls
        involved fails or if the program exits with non-zero status.
        (If the only problem was that the program exited non-zero
        C<$!> will be set to C<0>.)


Since /bin/false exited with non-zero status, $! should be set to 0.
However, it is instead set to the empty string.

        open FH, "/bin/false |" or die "fork: $!";
        print ">> $_" while <FH>;
        my $rc = close FH;
        my $errstr = defined($!)  ? $!  : "undefined";
        $rc        = defined($rc) ? $rc : "undefined";
        print "close rc: ($rc); \$!: ($errstr); \$?: ($?)\n";

The output is:

        close rc: (); $!: (); $?: (256)

If there is any version of Perl that has ever set $! to 0, I cannot
find it.  Versions up through 5.003 set $! to `Illegal seek' (which I
guess is probably system-dependent) and versions 5.004 and later show
the behavior above.

[Please do not change anything below this line]

Site configuration information for perl 5.00503:

Configured by mjd at Sun Jan 23 14:15:22 EST 2000.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
    osname=linux, osvers=2.2.12, archname=i586-linux
    uname='linux plover 2.2.12 #10 mon nov 1 17:02:09 est 1999 i586 unknown '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
    cc='cc', optimize='-O2', gccversion=egcs-2.90.29 980515 (egcs-1.0.3 release)
    cppflags='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    ccflags ='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /shlib /lib /usr/lib
    libs=-lndbm -lgdbm -ldbm -ldb -ldl -lm -lc
    libc=/lib/, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:

@INC for perl 5.00503:

Environment for perl 5.00503:
    LANG (unset)
    LANGUAGE (unset)
    LOGDIR (unset)
    PERL_BADLANG (unset)
    SHELL=/bin/bash Perl Programming lists via nntp and http.
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