Rename multiple files based on pattern in Unix

Question

There are multiple files in a directory that begin with prefix fgh, for example:

fghfilea
fghfileb
fghfilec

I want to rename a

Answer 1

I would recommend using my own script, which solves this problem. It also has options to change the encoding of the file names, and to convert combining diacriticals to precomposed characters, a problem I always have when I copy files from my Mac.

#!/usr/bin/perl

# Copyright (c) 2014 André von Kugland

# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.

$help_msg =
"rename.pl, a script to rename files in batches, using Perl
           expressions to transform their names.
Usage:
    rename.pl [options] FILE1 [FILE2 ...]
Where options can be:
    -v                      Verbose.
    -vv                     Very verbose.
    --apply                 Really apply modifications.
    -e PERLCODE             Execute PERLCODE. (e.g. 's/a/b/g')
    --from-charset=CS       Source charset. (e.g. \"iso-8859-1\")
    --to-charset=CS         Destination charset. (e.g. \"utf-8\")
    --unicode-normalize=NF  Unicode normalization form. (e.g. \"KD\")
    --basename              Modifies only the last element of the path.
";

use Encode;
use Getopt::Long;
use Unicode::Normalize 'normalize';
use File::Basename;
use I18N::Langinfo qw(langinfo CODESET);

Getopt::Long::Configure ("bundling");

# ----------------------------------------------------------------------------------------------- #
#                                           Our variables.                                        #
# ----------------------------------------------------------------------------------------------- #

my $apply = 0;
my $verbose = 0;
my $help = 0;
my $debug = 0;
my $basename = 0;
my $unicode_normalize = "";
my @scripts;
my $from_charset = "";
my $to_charset = "";
my $codeset = "";

# ----------------------------------------------------------------------------------------------- #
#                                        Get cmdline options.                                     #
# ----------------------------------------------------------------------------------------------- #

$result = GetOptions ("apply" => \$apply,
                      "verbose|v+" => \$verbose,
                      "execute|e=s" => \@scripts,
                      "from-charset=s" => \$from_charset,
                      "to-charset=s" => \$to_charset,
                      "unicode-normalize=s" => \$unicode_normalize,
                      "basename" => \$basename,
                      "help|h|?" => \$help,
                      "debug" => \$debug);

# If not going to apply, then be verbose.
if (!$apply && $verbose == 0) {
  $verbose = 1;
}

if ((($#scripts == -1)
  && (($from_charset eq "") || ($to_charset eq ""))
  && $unicode_normalize eq "")
  || ($#ARGV == -1) || ($help)) {
  print $help_msg;
  exit(0);
}

if (($to_charset ne "" && $from_charset eq "")
  ||($from_charset eq "" && $to_charset ne "")
  ||($to_charset eq "" && $from_charset eq "" && $unicode_normalize ne "")) {
  $codeset = langinfo(CODESET);
  $to_charset = $codeset if $from_charset ne "" && $to_charset eq "";
  $from_charset = $codeset if $from_charset eq "" && $to_charset ne "";
}

# ----------------------------------------------------------------------------------------------- #
#         Composes the filter function using the @scripts array and possibly other options.       #
# ----------------------------------------------------------------------------------------------- #

$f = "sub filterfunc() {\n    my \$s = shift;\n";
$f .= "    my \$d = dirname(\$s);\n    my \$s = basename(\$s);\n" if ($basename != 0);
$f .= "    for (\$s) {\n";
$f .= "        $_;\n" foreach (@scripts);   # Get scripts from '-e' opt. #
# Handle charset translation and normalization.
if (($from_charset ne "") && ($to_charset ne "")) {
  if ($unicode_normalize eq "") {
    $f .= "        \$_ = encode(\"$to_charset\", decode(\"$from_charset\", \$_));\n";
  } else {
    $f .= "        \$_ = encode(\"$to_charset\", normalize(\"$unicode_normalize\", decode(\"$from_charset\", \$_)));\n"
  }
} elsif (($from_charset ne "") || ($to_charset ne "")) {
    die "You can't use `from-charset' nor `to-charset' alone";
} elsif ($unicode_normalize ne "") {
  $f .= "        \$_ = encode(\"$codeset\", normalize(\"$unicode_normalize\", decode(\"$codeset\", \$_)));\n"
}
$f .= "    }\n";
$f .= "    \$s = \$d . '/' . \$s;\n" if ($basename != 0);
$f .= "    return \$s;\n}\n";
print "Generated function:\n\n$f" if ($debug);

# ----------------------------------------------------------------------------------------------- #
#                 Evaluates the filter function body, so to define it in our scope.               #
# ----------------------------------------------------------------------------------------------- #

eval $f;

# ----------------------------------------------------------------------------------------------- #
#                  Main loop, which passes names through filters and renames files.               #
# ----------------------------------------------------------------------------------------------- #

foreach (@ARGV) {
  $old_name = $_;
  $new_name = filterfunc($_);

  if ($old_name ne $new_name) {
    if (!$apply or (rename $old_name, $new_name)) {
      print "`$old_name' => `$new_name'\n" if ($verbose);
    } else {
      print "Cannot rename `$old_name' to `$new_name'.\n";
    }
  } else {
    print "`$old_name' unchanged.\n" if ($verbose > 1);
  }
}