Rename multiple files at once (ksh88 and newer)

fr.ksh

#!/bin/ksh
#
# Copyright (c) 2010,2011,2012 Joachim de Groot <jdegroot@web.de>
#
# 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.

usage() {
	cat <<END
$0 [options] [operation] file...

  operation is one of:
  -a    Append the given value to the file names
  -c    Chop the given value off the end of the file names
  -n    Number given files
  -p    Prepend the given value to the file names
  -t    Trim the given value off the beginning of the file names

  Options:
  -d    dry run: show what would be done without touching anything
  -f    first number                       (numbering mode, default: 1)
  -o    offset between file numbers        (numbering mode, default: 1)
  -v    verbose
  -w    file number width, zero padded     (numbering mode, default: 1)

END
}


process() {
	while (( $# > 0 )); do
		FILE="$1"; shift
		FN=${FILE##*/}
		DN=${FILE%/*}

		# Remember if the file to be renamed is in the current directory.
		if [[ "$FN" != "$DN" ]]; then
			NEED_PATH=1
		else
			NEED_PATH=0
		fi


		# generate new file name:
		# process the desired changes
		if [[ -n "$NUMBER" ]]; then
			FN=$(printf "%0${WIDTH}d" $START)
			START=$(( $START + $OFFSET ))
		fi

		if [[ -n "$TRIM" ]]; then
			FN=${FN#"$TRIM"}
		fi

		if [[ -n "$CHOP" ]]; then
			FN=${FN%"$CHOP"}
		fi

		if [[ -n "$PREPEND" ]]; then
			FN="$PREPEND""$FN"
		fi

		if [[ -n "$APPEND" ]]; then
			FN="$FN""$APPEND"
		fi

		# Assemble the file's new name
		if [[ "$NEED_PATH" -eq 1 ]]; then
			NEW_NAME="$DN"/"$FN"
		else
			NEW_NAME="$FN"
		fi

		rename "$FILE" "$NEW_NAME"
	done
}


rename() {
	OLD="$1"; shift;
	NEW="$1"; shift;

	if [[ "$OLD" = "$NEW" ]]; then
		# no pattern matched, silently fail
		return
	fi

	if [[ ! -f "$OLD" ]]; then
		echo "$OLD: file not found."
		return
	fi

	if [[ ! -w "$OLD" ]]; then
		echo "$OLD: no write permission."
		return
	fi

	if [[ -f "$NEW" ]]; then
		echo "Cannot rename $OLD to $NEW: file exists."
		return
	fi

	if [[ -n "$VERBOSE" || -n "$DRY_RUN" ]]; then
		echo "'$OLD' -> '$NEW'"
	fi

	if [[ -z "$DRY_RUN" ]]; then
		mv "$OLD" "$NEW"
	fi
}

# Parameters for numbering files
typeset -i START=1
typeset -i OFFSET=1
typeset -i WIDTH=1

# Parse command line
while getopts "a:c:df:hno:p:t:vw:" OPTION; do
	case $OPTION in
		# OP: append param to the file name
		a)
			APPEND="$OPTARG"
		;;

		# OP: chop param from end of file name
		c)
			CHOP="$OPTARG"
		;;

		# OPTION: dry run
		d)
			DRY_RUN="y"
		;;


		# OPTION: First number
		f)
			START="$OPTARG"
		;;

		# OP: help
		h)
			usage
			exit
		;;

		# OP: number files
		n)
			NUMBER="y"
		;;

		# OPTION: Numbering offset
		o)
			OFFSET="$OPTARG"
		;;

		# OP: prepend value to file name
		p)
			PREPEND="$OPTARG"
		;;

		# OP: trim param off the start of file name
		t)
			TRIM="$OPTARG"
		;;

		# OPTION: verbose
		v)
			VERBOSE="y"
		;;

		# OPTION: Number width
		w)
			WIDTH="$OPTARG"
		;;

		# Unknown switch
		*)
			usage
			exit 1
		;;
	esac
done

# Removed parsed command line arguments
shift $(( $OPTIND - 1 ))

# Bail out if not supplied with file names
if (( $# == 0 )); then
	usage
	exit 1
fi

# Call function with remaining parameters
process "$@"

fr - rename multiple files

fr is a Korn shell script which allows to rename multiple files.
It is known to work with current ksh versions, but also with ksh88 on
Solaris 2.8 and OSF/1 4.0.

Available functions are:

• add or remove a filename prefix
• add or remove a filename suffix
• number files