maddening system call gzip/gunzip problems

[neilwatson]

I have a directory where all files, except .txt, are gzipped. I want to have Perl gunzip them, process them and then gzip them again. I've stripped out all the middle process to attempt to debug the problem.

#!/usr/bin/perl

use warnings;
use strict;
use Date::Calc qw(:all);

my $PRINTFILE_DIRECTORY = "/home/lprjob1/filest";

# Directories to work in
#my @dirs = ('dpi', 'dsc', 'dscpprod');
my @dirs = ('dscpprod');
my $dir;

my ($year, $month, $day, $control_file, $pday, $pdatestr);

# Form date string with arguement or default to today.
my $dateform;
if (scalar(@ARGV) eq 1 && $ARGV[0] =~ /\d\d\d\d-\d\d-\d\d/) {
    $dateform = $ARGV[0];
}
else {
    ($year, $month, $day) = Today();
    $dateform = sprintf("%d-%02d-%02d",$year,$month,$day);

    # Create current previous day's date string for later use
    # This will be needed for the control file.
    $pday = $day - 1;
    $year =~ s/^\d{2}(\d{2})/$1/;
    $pdatestr = sprintf("%02d%02d%02d",$year,$month,$pday);
    $control_file = "CONTROL_$pdatestr.txt";
}

foreach (@dirs){

    $dir = $_;

    print "Should $dir be processed?\n";
    #If the control file does not exist then skip
    next unless ( -e "$PRINTFILE_DIRECTORY/$dir.$dateform/$control_fil
+e" );
    print "Yes, $dir should be processed?\n";

    # Unzip files
    gzip('unzip', "$PRINTFILE_DIRECTORY/$dir.$dateform");

    # Zip files again
    gzip('zip', "$PRINTFILE_DIRECTORY/$dir.$dateform");
}

sub gzip {
    my $cmd = shift;
    my $dir = shift;
    my $file;
    my $fullfile;
    print "$cmd files in $dir...\n";

    # Make sure command is secure and predictable.
    if ( $cmd eq 'zip' ){
        $cmd = 'gzip';
    } elsif ( $cmd eq 'unzip' ){
        $cmd = 'gunzip';
    } else {
        warn "zip or unzip command not given $!";
    }

    opendir DIR, $dir or warn "Cannot open $dir $!";
    while ( defined ( $file = readdir(DIR) ) ){
    
        $fullfile = "$dir/$file";
        if ( !-f $fullfile || $file =~ m/\.txt$/ || $file !~ m/^[\w-]+
+(\.[\w-]+)*$/ ){
            print "skipping $fullfile\n";
            next;
        }

        #print "$cmd $fullfile";
        system ( "$cmd $fullfile") == 0 or warn "Cannot $cmd $fullfile
+ : $!";
    }
    closedir DIR;
}

I consistently get seemingly random errors.

[lprjob1@tor-lx-sftp report-printing]$ ./test.pl 
Should dscpprod be processed?
Yes, dscpprod should be processed?
unzip files in /home/lprjob1/filest/dscpprod.2006-12-07...
skipping /home/lprjob1/filest/dscpprod.2006-12-07/.
skipping /home/lprjob1/filest/dscpprod.2006-12-07/..
skipping /home/lprjob1/filest/dscpprod.2006-12-07/CONTROL_061206.txt
gunzip: /home/lprjob1/filest/dscpprod.2006-12-07/cns061206: unknown su
+ffix -- ignored
Cannot gunzip /home/lprjob1/filest/dscpprod.2006-12-07/cns061206 :  at
+ ./test.pl line 75.
skipping /home/lprjob1/filest/dscpprod.2006-12-07/print.files.txt
skipping /home/lprjob1/filest/dscpprod.2006-12-07/print.archive.txt
zip files in /home/lprjob1/filest/dscpprod.2006-12-07...
skipping /home/lprjob1/filest/dscpprod.2006-12-07/.
skipping /home/lprjob1/filest/dscpprod.2006-12-07/..
skipping /home/lprjob1/filest/dscpprod.2006-12-07/CONTROL_061206.txt
gzip: /home/lprjob1/filest/dscpprod.2006-12-07/dd061206.gz already has
+ .gz suffix -- unchanged
Cannot gzip /home/lprjob1/filest/dscpprod.2006-12-07/dd061206.gz :  at
+ ./test.pl line 75.
skipping /home/lprjob1/filest/dscpprod.2006-12-07/print.files.txt
skipping /home/lprjob1/filest/dscpprod.2006-12-07/print.archive.txt
gzip: /home/lprjob1/filest/dscpprod.2006-12-07/dl061206.GGDHSETD.gz al
+ready has .gz suffix -- unchanged
Cannot gzip /home/lprjob1/filest/dscpprod.2006-12-07/dl061206.GGDHSETD
+.gz :  at ./test.pl line 75.
gzip: /home/lprjob1/filest/dscpprod.2006-12-07/dq061206.new.gz already
+ has .gz suffix -- unchanged
Cannot gzip /home/lprjob1/filest/dscpprod.2006-12-07/dq061206.new.gz :
+  at ./test.pl line 75.
gzip: /home/lprjob1/filest/dscpprod.2006-12-07/hs061206.v4.gz already 
+has .gz suffix -- unchanged
Cannot gzip /home/lprjob1/filest/dscpprod.2006-12-07/hs061206.v4.gz : 
+ at ./test.pl line 75.
gzip: /home/lprjob1/filest/dscpprod.2006-12-07/ncdsc061206.gz already 
+has .gz suffix -- unchanged

I see no pattern to the errors. The files associated with the errors are different each time. What have I missed?