#!/bin/ksh
# @(#) efn.ksh 93/04/13
# 93/04/13 john h. dubois iii (john@armory.com)

TMP=${TMP:-$TMPDIR}
TMP=${TMP:-/tmp}
VISUAL=${VISUAL:-$EDITOR}
VISUAL=${VISUAL:-vi}

tmpfile=$TMP/efn$$
name=${0##*/}
Usage="Usage: $name [-h] [-f <file>] filename ..."
InFile=

while getopts :hf: opt; do
    case $opt in
    h)
	echo \
"$name: edit file names.
$Usage
Each file name given is put into a file preceded by a numeric tag to
identify it.  The file is then passed to the user's editor (the value of
\$VISUAL or \$EDITOR if set; vi if not).  The file names may be changed
while in the editor.  The tags should not be changed.  When the editor is
exited, the file is scanned for changed names.  For each name that has
been changed, the name of the file it refers to is changed to the new name.  
Options:
-f: Take file names to be edited from <file> instead of the command line.
-h: print this help."
       exit 0
       ;;
    f)
	if [ ! -r "$OPTARG" ]; then
	    echo "$OPTARG: Cannot read."
	    exit 1
	fi
	InFile=$OPTARG
	;;
    +?)
	echo "$name: options should not be preceded by a '+'."
	exit 1
	;;
    ?) 
	echo "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done
 
# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

if [ -n "$InFile" ]; then
    if [ $# -gt 0 ]; then
	echo \
"File names should not be given on the command line if -f <filename> is used."
	exit 1
    fi
    set -- $(<$InFile)
fi

if [ $# -lt 1 ]; then
    echo "$Usage\nUse -h for help."
    exit
fi

echo "Change each filename to the name the file should be moved to." > $tmpfile
typeset -i sequence=0 numfiles

set -A Files -- "$@"

trap "rm $tmpfile; exit 0" HUP INT QUIT TERM

for file; do
    if [[ -a "$file" ]]; then
	let sequence+=1
	Files[sequence]=$file
	print "$sequence)\t$file"
    else
	print -u2 "$file: No such file."
    fi
done >> $tmpfile

numfiles=sequence

if [ numfiles -eq 0 ]; then
    rm $tmpfile
    exit 0
fi

[[ "$VISUAL" = *vi ]] && VISUAL="$VISUAL +2"

[ -s $tmpfile ] && $VISUAL $tmpfile

IFS="	"

while read tag newname; do
    case "$tag" in
    Change*)
	continue ;;
    +([0-9])\))
	sequence=${tag%\)}
	;;
    *)
	print -u2 "Editing error: unrecognized tag: $tag"
	continue;;
    esac
    oldname=${Files[sequence]}
    if [ "$oldname" = "$newname" ]; then
	print -- "Not moved: $oldname"
    else
	[[ "$oldname" = -* ]] && oldname="./$oldname"
	print "Moving $oldname to $newname"
	mv "$oldname" "$newname"
    fi
done < $tmpfile
rm $tmpfile
exit 0