#!/bin/bash
-# Copyright (C) 2014 Ian Kelling
+# Copyright (C) 2014-2016 Ian Kelling
# This program is under GPL v. 3 or later, see <http://www.gnu.org/licenses/>
+_lnf_existing_link() {
+ local target dest_file dest_dir
+ target="$1"
+ dest_file="$2"
+ dest_dir="$3"
+ if [[ -L $dest_file ]]; then
+ if [[ $(readlink $dest_file) == "$target" ]]; then
+ # Leave the link in place, but make sure it's
+ # owner & group is as if we created it.
+ # links all get 777 perms, so
+ # we already know that is right.
+
+ # test for setgid.
+ if [[ $(stat -L -c%a "$dest_dir") == 2??? ]]; then
+ grp=$(stat -L -c%g "$dest_dir") || return $?
+ else
+ grp=$(id -g) || return $?
+ fi
+ if [[ $EUID == 0 && $(stat -c%u "$dest_file") != 0 ]]; then
+ chown -h 0:$grp "$dest_file" || return $?
+ elif [[ $(stat -c%g "$dest_file") != "$grp" ]]; then
+ chgrp -h $grp "$dest_file" || return $?
+ fi
+ do_exit=true
+ return 0
+ fi
+ to_remove+=("$dest_file")
+ elif [[ -e $dest_file ]]; then
+ to_remove+=("$dest_file")
+ fi
+ to_link+=("$target")
+}
lnf() {
- local help="lnf [--help] LN_ARGUMENTS...
-Create symlinks conveniently and forcefully.
-Remove existing file/links using trash-put or rm -rf if it is not available.
-Create directory if needed. Finally, ln -s -- LN_ARGUMENTS"
- if [[ $1 == --help ]]; then
+ local help="Usage:
+ lnf [OPTIONS] -T TARGET LINK_NAME (1st form)
+ lnf [OPTIONS] TARGET (2nd form)
+ lnf [OPTIONS] TARGET... DIRECTORY (3rd form)
+Create symlinks forcefully
+
+If the link already exists, make it's ownership be the same as if it was
+newly created (only chown if we are root). Removes existing files using
+trash-put or rm -rf if it is not available, or if trash-put fails due to a
+limitation such as a cross-filesystem link. Create directory of link if
+needed. Slightly more restrictive arguments than ln.
+
+In the 1st form, create a link to TARGET with the name LINK_NAME. In the 2nd
+form, create a link to TARGET in the current directory. In the 3rd form, create
+links to each TARGET in DIRECTORY.
+
+-n|--dry-run Do verbose dry run.
+-v|--verbose Print commands which modify the filesystem.
+-h|--help Print help and exit.
+"
+
+
+ local temp nodir
+ local verbose=false
+ local dry_run=false
+ local do_exit=false
+ temp=$(getopt -l help,dry-run,verbose hnTv "$@") || usage 1
+ eval set -- "$temp"
+ while true; do
+ case $1 in
+ -n|--dry-run) dry_run=true; verbose=true; shift ;;
+ -T) nodir=-T; shift ;;
+ -v|--verbose) verbose=true; shift ;;
+ -h|--help) echo "$help"; return 0 ;;
+ --) shift; break ;;
+ *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
+ esac
+ done
+
+ if (( $# == 0 )); then
echo "$help"
- return 0
- fi
-
- local remove x
- if type -P dircolors >/dev/null; then
- remove=trash-put
- else
- remove="rm -rf"
- fi
-
- if [[ $# -ge 3 && ! -d ${!#} ]]; then
- mkdir -p "${!#}"
- elif [[ $# -ge 2 && -d ${!#} ]]; then
- local oldcwd=$PWD
- cd ${!#} # last arg
- for x in "${@:1:$(($#-1))}"; do # all but last arg
- # remove any trailing slashes
- x="${x%%+(/)}"
- # remove any leading directory components
- x="${x##*/}"
- [[ -e "$x" || -L "$x" ]] && $remove "$x"
- done
- cd "$oldcwd"
- elif [[ $# -eq 2 ]]; then
- if [[ -e "$2" || -L "$2" ]]; then
- $remove "$2"
- elif [[ ! -d "$2/.." ]]; then
- mkdir -p "$2/.."
+ return 1
+ fi
+
+ if [[ $nodir ]]; then
+ if (( $# != 2 )); then
+ echo "lnf: error: expected 2 arguments with -T flag. Got $#"
+ return 1
fi
+ fi
+
+ local reset_extglob=false
+ ! shopt extglob >/dev/null && reset_extglob=true
+ shopt -s extglob
+
+
+ local -a to_remove to_link
+ local x ret prefix dest_dir grp target
+ local mkdir=false
+
+ if [[ $nodir ]]; then
+ dest_file="$2"
+ dest_dir="$(dirname "$dest_file")"
+ _lnf_existing_link "$1" "$dest_file" "$dest_dir" || return $?
+ if $do_exit; then return 0; fi
+ if [[ ! -d $dest_dir ]]; then
+ mkdir=true
+ if [[ -e $dest_dir || -L $dest_dir ]]; then
+ to_remove+=("$dest_dir")
+ fi
+ fi
+ to_link+=("$dest_file")
+ elif (( $# >= 2 )); then
+ dest_dir="${!#}"
+ if [[ -d $dest_dir ]]; then
+ prefix="$dest_dir" # last arg
+ for target in "${@:1:$(( $# - 1 ))}"; do # all but last arg
+ # Remove 1 or more trailing slashes, using.
+ dest_file="${target%%+(/)}"
+ # remove any leading directory components, add prefix
+ dest_file="$prefix/${target##*/}"
+ _lnf_existing_link "$target" "$dest_file" "$dest_dir"
+ done
+ else
+ to_link+=("${@:1:$(( $# - 1 ))}")
+ mkdir=true
+ fi
+ if (( ${#to_link[@]} == 0 )); then
+ return 0
+ fi
+ to_link+=("$dest_dir")
elif [[ $# -eq 1 ]]; then
- [[ -e "${1##*/}" || -L "${1##*/}" ]] && $remove "${1##*/}"
+ dest_file="${1##*/}"
+ _lnf_existing_link "$1" "$dest_file" . || return $?
+ if $do_exit; then return 0; fi
+ fi
+ if (( ${#to_remove[@]} >= 1 )); then
+ if type -P trash-put >/dev/null; then
+ if $verbose; then
+ echo "lnf: trash-put -- ${to_remove[*]}"
+ fi
+ if ! $dry_run; then
+ trash-put -- "${to_remove[@]}" || ret=$?
+ fi
+ # trash-put will fail to trash a link that goes across filesystems (72),
+ # and for empty files (74)
+ # so revert to rm -rf in that case
+ if [[ $ret == 72 ]]; then
+ echo "lnf: using rm -rf to overcome cross filesystem trash-put limitation"
+ rm -rf -- "${to_remove[@]}" || return $?
+ elif [[ $ret == 74 ]]; then
+ echo "lnf: using rm -rf to overcome empty file & hardlink trash-put limitation"
+ rm -rf -- "${to_remove[@]}"
+ elif [[ $ret && $ret != 0 ]]; then
+ return $x
+ fi
+ else
+ if $verbose; then
+ echo "lnf: rm -rf -- ${to_remove[*]}"
+ fi
+ if ! $dry_run; then
+ rm -rf -- "${to_remove[@]}"
+ fi
+ fi
+ fi
+
+ $reset_extglob && shopt -u extglob
+
+ if $mkdir; then
+ if $verbose; then
+ echo "lnf: mkdir -p $dest_dir"
+ fi
+
+ if ! $dry_run && ! mkdir -p "$dest_dir"; then
+ echo "lnf error: failed to make directory $dest_dir"
+ return 1
+ fi
+ fi
+
+ if $verbose; then
+ echo "lnf: ln -s $nodir -- ${to_link[*]}"
+ fi
+ if ! $dry_run; then
+ ln -s $nodir -- "${to_link[@]}"
fi
- ln -s -- "$@"
}
lnf "$@"
iankelling.org / git / lnf / blobdiff