Rabu, 12 Mei 2010

perlmv: Renaming files with Perl code

perlmv is a script which I have personally been using all the time for years, but has only been uploaded to CPAN today. The concept is very simple, to rename files by manipulating $_ in specified Perl code. For example, to rename all .avi files to lowercase,

$ perlmv -de '$_=lc' *.avi

The -d option is for dry-run, so that we can test our code before actually renaming the files. If you are sure that the code is correct, remove the -d (or replace it with -v, for verbose).

perlmv can also save your code into scriptlets (files in ~/.perlmv/scriptlets/), so if you do:

$ perlmv -e 's/\.(jpe?g|jpe)$/.jpg/i' -W normalize-jpeg

You can later do this:

$ perlmv -v normalize-jpeg *.JPG *.jpeg

In fact, perlmv comes with several scriptlets you can use (more useful scriptlets will be added in the future):

$ perlmv -L

Let me know if you have tried out the script.

4 komentar:

  1. You've reinvented the wheel. Debian ships with a "rename" utility that does exactly this and it is written Perl, based on an example from Larry even. I've included it below:

    #!/usr/bin/perl -w
    # This script was developed by Robin Barker (Robin.Barker@npl.co.uk),
    # from Larry Wall's original script eg/rename from the perl source.
    # This script is free software; you can redistribute it and/or modify it
    # under the same terms as Perl itself.
    # Larry(?)'s RCS header:
    # RCSfile: rename,v Revision: 4.1 Date: 92/08/07 17:20:30
    # $RCSfile: rename,v $$Revision: 1.5 $$Date: 1998/12/18 16:16:31 $
    # $Log: rename,v $
    # Revision 1.5 1998/12/18 16:16:31 rmb1
    # moved to perl/source
    # changed man documentation to POD
    # Revision 1.4 1997/02/27 17:19:26 rmb1
    # corrected usage string
    # Revision 1.3 1997/02/27 16:39:07 rmb1
    # added -v
    # Revision 1.2 1997/02/27 16:15:40 rmb1
    # *** empty log message ***
    # Revision 1.1 1997/02/27 15:48:51 rmb1
    # Initial revision

    use strict;

    use Getopt::Long;

    my ($verbose, $no_act, $force, $op);

    die "Usage: rename [-v] [-n] [-f] perlexpr [filenames]\n"
    unless GetOptions(
    'v|verbose' => \$verbose,
    'n|no-act' => \$no_act,
    'f|force' => \$force,
    ) and $op = shift;

    $verbose++ if $no_act;

    if (!@ARGV) {
    print "reading filenames from STDIN\n" if $verbose;
    @ARGV = ;

    for (@ARGV) {
    my $was = $_;
    eval $op;
    die $@ if $@;
    next if $was eq $_; # ignore quietly
    if (-e $_ and !$force)
    warn "$was not renamed: $_ already exists\n";
    elsif ($no_act or rename $was, $_)
    print "$was renamed as $_\n" if $verbose;
    warn "Can't rename $was $_: $!\n";


    =head1 NAME

    rename - renames multiple files

    =head1 SYNOPSIS

    B S<[ B<-v> ]> S<[ B<-n> ]> S<[ B<-f> ]> I S<[ I ]>

    =head1 DESCRIPTION

    renames the filenames supplied according to the rule specified as the
    first argument.
    The I
    argument is a Perl expression which is expected to modify the C<$_>
    string in Perl for at least some of the filenames specified.
    If a given filename is not modified by the expression, it will not be
    If no filenames are given on the command line, filenames will be read
    via standard input.

    For example, to rename all files matching C<*.bak> to strip the extension,
    you might say

    rename 's/\.bak$//' *.bak

    To translate uppercase names to lower, you'd use

    rename 'y/A-Z/a-z/' *

    =head1 OPTIONS

    =over 8

    =item B<-v>, B<--verbose>

    Verbose: print names of files successfully renamed.

    =item B<-n>, B<--no-act>

    No Action: show what files would have been renamed.

    =item B<-f>, B<--force>

    Force: overwrite existing files.


    =head1 ENVIRONMENT

    No environment variables are used.

    =head1 AUTHOR

    Larry Wall

    =head1 SEE ALSO

    mv(1), perl(1)

    =head1 DIAGNOSTICS

    If you give an invalid Perl expression you'll get a syntax error.

    =head1 BUGS

    The original C did not check for the existence of target filenames,
    so had to be used with care. I hope I've fixed that (Robin Barker).


  2. @NPEREZ: Thanks for the comment. Actually I am aware of 'rename', from back when reading Learning Perl/Programming Perl. But surely one can invent a better wheel? When I first wrote this script I want recursive renaming and automatic adding of ".1", ".2", etc. The script grew from there.

    Btw, I do forget about the original rename. Will be mentioning it in the POD for next release. Thanks.

  3. It surely has nice extensions and some additional conveniences and it would be nice if the population at large using the original one could use them as well. I don't want to interfere too much with your judgement as to what power you want to have over the project - but maybe if you contacted Robin Barker - then maybe he would agree to incorporate your additions?

  4. @zby: Thanks for the suggestion. Email sent :-)