in reply to Re: Bring out your Old Perl Code
in thread Bring out your Old Perl Code

I personally believe one may also play with some code from http://dev.perl.org/perl1/dist/example.gz (which I found mentioned in a recent post.) Actually it would be interesting to rewrite equivalent code in pre-5.10 Perl 5 code, in 5.10 if it has some advantage, and perhaps in Perl 6 if it is interesting. I'm skipping gsh and trying some of the shorter examples:

        #!/bin/perl
    open(goners,"find . -mtime +14 -print|");
    while (<goners>) {
        chop;
        unlink;
    }

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Ah! Larry, Larry! You must be a n00b ;) Don't we suggest the use of File::Find and relatives all the time?

#!/usr/bin/perl

use strict;
use warnings;
use File::Find;
use 5.010;

find { no_chdir => 1,
       wanted => sub { unlink if -f -M > 14 } }, '.';

__END__

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(I don't think you want to unlink directories, anyway, don you?)

    #!/bin/perl

    die "Usage: euthanasia directory days" unless $#ARGV == 1;

    ($dir, $days) = @ARGV;        # assign array to list of variables

    die "Can't find directory $dir" unless chdir $dir;

    open(goners,"find . -mtime +$days -print|") || die "Can't run find
+";
    while (<goners>) {
        chop;
        unlink;
    }

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#!/usr/bin/perl

use strict;
use warnings;
use File::Find;
use File::Basename;
use 5.010;

BEGIN {
    my $name = basename $0; 
    sub USAGE () { "Usage: $name <directory> <days>\n" }
}

die USAGE unless @ARGV == 2;
my ($dir, $days) = @ARGV;

find { no_chdir => 1,
       wanted => sub { unlink if -f -M > $days } }, $dir;

__END__

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And now, I'm half way through working on scan_df but I must get out of my house in a few minutes, so I'll complete that later...

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Re^3: Bring out your Old Perl Code
by blazar (Canon) on Dec 29, 2007 at 22:17 UTC
    And now, I'm half way through working on scan_df but I must get out of my house in a few minutes, so I'll complete that later...

    I personally believe it's ready now. Please note that my rewriting of the original script reflects my own personal preferences and is in no way intended to claim that it shows the Right™ WTDI. Also double check for errors since fundamentally I only made sure that it passes -c.

    First, the original script:

    Read more... (2 kB)

    And then, the rewriting:

    #!/usr/bin/perl

use strict;
use warnings;
use File::Basename;
use Getopt::Std;

my $name;
BEGIN { 
    $name = basename $0;
    sub USAGE () { <<".EOT"; }
$name [options]
      
Current options are:
      
    -m   Assume mc300, mc500 or mc700
    -h   Print this help screen and exit
.EOT
}

my %opts;
getopts 'mh' => \%opts;
print(USAGE), exit if $opts{h};

my $dir = '/usr/adm/private/memories';
my $olddf = 'olddf';

chdir $dir or die "[$name] Can't cd into `$dir': $!\n";
defined(my $newdf = qx/df/) or die "[$name] Can't run df: $!\n!";

my %oldused = map {
    my ($fs,undef,$used)=split;
    $fs =~ /:/ ? () : $fs => $used;
} do { 
    open my $df, '<', $olddf or die "[$name] Can't open `$olddf': $!\n
+";
    <$df> 
};

open my $df, '<', \$newdf or die "[$name] Can't open file in memory: $
+!\n";

while (<$df>) {
    my ($fs, $kbytes, $used, $avail, $capacity, $mounted_on) = split;
    next if $fs =~ /:/;
    my $oldused = $oldused{$fs};
    next if ($oldused == $used and $capacity < 99);    # inactive file
+system
    if ($capacity >= 90) {
        if ($opts{m}) {
            substr($_,13,0) = ' ' x 8;
            $_ /= 2 for $kbytes, $used, $oldused, $avail;
        }
    my $diff = int($used - $oldused);
        $mounted_on .= ' *' if $avail < 2*$diff;
    next if $diff < 50 && $mounted_on eq '/';
    $fs =~ s|/dev/||;
        $diff = '(' . ($diff >=0 ? '+' : '') . "$_)";
    printf "%-8s%8d%8d %-8s%8d%7s    %s\n" =>
          $fs, $kbytes, $used, $diff, $avail, $capacity, $mounted_on;
    }
}

open my $odf, '>', $olddf or die "[$name] Can't open `$olddf': $!\n";
print $odf $newdf;

__END__

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