X-Git-Url: https://iankelling.org/git/?p=lnf;a=blobdiff_plain;f=lnf;h=0620b32929d87c19ef5f79217094a9012f3df3ce;hp=fa9b59937108e5b6514cd983d629c3d4f8bfc34b;hb=HEAD;hpb=15c4639b1ee74247ac931088eea77e3ea37ba7c3

diff --git a/lnf b/lnf
index fa9b599..28f77ee 100755
--- a/lnf
+++ b/lnf
@@ -1,46 +1,181 @@
 #!/bin/bash
-# Copyright (C) 2014 Ian Kelling
-# This program is under GPL v. 3 or later, see <http://www.gnu.org/licenses/>
+# I, Ian Kelling, follow the GNU license recommendations at
+# https://www.gnu.org/licenses/license-recommendations.en.html. They
+# recommend that small programs, < 300 lines, be licensed under the
+# Apache License 2.0. This file contains or is part of one or more small
+# programs. If a small program grows beyond 300 lines, I plan to switch
+# its license to GPL.
 
+# Copyright 2024 Ian Kelling
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+_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 [[ $1 == --help ]]; then
-        echo "$help"
-        return 0
-    fi
-    
-    local remove x
-    if type -P dircolors >/dev/null; then
-        remove=trash-put
+  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
+rm -rf. 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 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 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
-        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/.."
-        fi
-    elif  [[ $# -eq 1 ]]; then
-        [[ -e "${1##*/}" || -L "${1##*/}" ]] && $remove "${1##*/}"
-    fi
-    ln -s -- "$@"
+      to_link+=("${@:1:$(( $# - 1 ))}")
+      mkdir=true
+    fi
+    if (( ${#to_link[@]} == 0 )); then
+      return 0
+    fi
+    to_link+=("$dest_dir")
+  elif  [[ $# -eq 1 ]]; then
+    dest_file="${1##*/}"
+    _lnf_existing_link "$1" "$dest_file" . || return $?
+    if $do_exit; then return 0; fi
+  fi
+  if (( ${#to_remove[@]} >= 1 )); then
+    if $verbose; then
+      echo "lnf: rm -rf -- ${to_remove[*]}"
+    fi
+    if ! $dry_run; then
+      rm -rf -- "${to_remove[@]}"
+    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
 }
 lnf "$@"