in reply to maddening system call gzip/gunzip problems

There are easier ways to do certain parts of your existing program. If you want to find all gzip'd files in a directory, use File::Find: 
use File::Find;
my $dir = "/home/lprjob1/filest"
find( sub { push @files, $File::Find::name if -f && /.+gz/ }, $dir );

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Then I would look into using some of the CPAN modules associated with gzip like Tie::Gzip. If the files you are looking to process are text files, you can tie them to a gzip'd filehandle and read them: 

use Tie::Gzip;
 for my $log (@files) {
   tie *LOG, 'Tie::Gzip';
   open (\*LOG, '<', "$log") or die("Cannot open $log: $!");
   while (my $line = <LOG>) {
     # Iterate over the files here and do blah
   }
   close (LOG);
   untie *LOG;
 }

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Re^2: maddening system call gzip/gunzip problems
by graff (Chancellor) on Dec 08, 2006 at 02:09 UTC
    If you want to find all gzip'd files in a directory, use File::Find:

    (sigh) No. Stick with readdir, like the OP wants, but use it with grep. And as for actually handling the data, my favorite is PerlIO::gzip: 

        my @target_files;
    my ( $imode, $omode );
    opendir DIR, $dir or warn "Cannot open $dir $!";
    if ( $cmd eq 'gzip' ) {
        @target_files = grep { !/\.gz$/ and -f "$dir/$_" } readdir DIR
+;
        $imode = "<";
        $omode = ">:gzip";
    }
    else {
        @target_files = grep /.\.gz$/, readdir DIR;
        $imode = "<:gzip";
        $omode = ">";
    }
    closedir DIR;

    for my $ifile ( @target_files ) {
        my $ofile;
        if ( $cmd eq 'gzip' ) {
            $ofile .= ".gz";
        } else {
            $ofile =~ s/\.gz$//;
        }
        open( I, $imode, $ifile ) or die "$ifile: $!";
        open( O, $omode, $ofile ) or die "$ofile: $!";
        while(<I>) { print O }
        close I;
        close O;
        unlink $ifile;
     }

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    (update: Having read the later replies after I posted this, I should point out that this approach (using grep with readdir) avoids the problem of modifying the directory contents before being completely done with readdir -- we get all the files into an array first, then work on the files. I did update my code snippet to put an explicit "closedir" before the "for" loop, to clarify this point.)

    UPDATE: (2010-10-18) It seems that PerlIO::gzip should be viewed as superseded by PerlIO::via:gzip. (see PerlIO::gzip or PerlIO::via::gzip).

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