rename

#!/usr/bin/perl
require "getopts.pl";

&Getopts("spPSva");

if (($#ARGV == -1) || ($#ARGV > 1)){ # echo help
    print STDERR "Usage:\t$0 [-spSPva] <from> [<to>]\n";
    print STDERR "\n";
    print STDERR "-lowercase\tsuffix or prefix \"from\" string\n";
    print STDERR "-uppercase\tsuffix or prefix \"to\" string\n";
    print STDERR "-v\t\tverbose mode\n";
    print STDERR "-a\t\tappend mode\n";
    print STDERR "\n";
    exit 0;
}

$mode = ($opt_p) ? 0 : 1;
$rmode = ($opt_P) ? 0 : 1;
$to = (defined $ARGV[1]) ? $ARGV[1] : "";
$from = $ARGV[0];

if ($opt_v && $mode == 1) {
    print STDERR "Switching files with suffix $from";
} elsif ($opt_v && $mode == 0) {
    print STDERR "Switching files with prefix $from";
}

if ($opt_v && $rmode == 1) {
    print STDERR "to suffix $to...\n";
} elsif ($opt_v && $rmode == 0) {
    print STDERR "to prefix $to...\n";
}


open (DIR, "ls -1 |");

$hit = 0;
while (<DIR>) {
    chop;
    $old = $_;
    $new = $_;
    if ($mode == 0 && /^$from/) {               # prefix find
        $hit++;
        if ($rmode == 0 && $opt_a) {
            system ("mv \"$old\" \"$to$old\"");
        } elsif ($rmode == 0) {
            $new =~ s/^$from/$to/;
            system ("mv \"$old\" \"$new\"");
        } else {
            system ("mv \"$old\" \"$old$to\"");
        }
    } elsif ($mode == 1 && /$from$/) {
        $hit++;
        if ($rmode == 1 && $opt_a) {
            system ("mv \"$old\" \"$old$to\"");
        } elsif ($rmode == 1) {
            $new =~ s/$from$/$to/;
            system ("mv \"$old\" \"$new\"");
        } else {
            system ("mv \"$old\" \"$old$to\"");
        }
    }
}

print stderr "Total of $hit files processed\n";

close (DIR);