X-Git-Url: https://iankelling.org/git/?a=blobdiff_plain;f=path_add-function;h=540306ca03f0d8aed9af772b7840696f38973fce;hb=0b6d44c7f3d567e0a26138509c8a24cb57c69b50;hp=428e2ecabc2faef3359efcb6cd61783ae32ae50b;hpb=fd19384f0fa703aacbe21d0bf1f086186bcd5936;p=distro-setup

diff --git a/path_add-function b/path_add-function
index 428e2ec..540306c 100644
--- a/path_add-function
+++ b/path_add-function
@@ -1,20 +1,42 @@
 #!/bin/bash
-# no bashisms so it can be used in debian profile run by dash
-# --start adds to start of path, which will give it highest priority
-# --ifexists will add to path only if the directory exists
+# Copyright (C) 2016 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.
+
+
+# avoiding bashisms so it can be used in edge cases where I don't have bash,
+# however, I'm not super confident that I've avoided them all
+#
 path_add() {
-    local found x y z ifexists start loop
+    local help="usage: path_add [options] PATH
+--help:     print this
+--end:      adds to end of path, which will give it lowest priority
+--ifexists: add to path only if directory exists"
+    local found x y z ifexists end loop newpath
     ifexists=false
-    start=false
+    end=false
     loop=true
     # portable substring matching is ugly http://mywiki.wooledge.org/BashFAQ/041
     while $loop; do
         case $1 in
             --*)
-                if [ "$1" = --start ]; then
-                    start=true
+                if [ "$1" = --end ]; then
+                    end=true
                 elif [ "$1" = --ifexists ]; then
                     ifexists=true
+                elif [ "$1" = --help ]; then
+                    echo "$help"
+                    return
                 fi
                 shift
                 ;;
@@ -23,22 +45,35 @@ path_add() {
                 ;;
         esac
     done
-    for x in "$@"; do
-        found=false
-        IFS=:
-        for y in $PATH; do
-            [ "$x" = "$y" ] && found=true
+    IFS=:
+    # build up the path without the components we want to add
+    for y in $PATH; do
+        for x in "$@"; do
+            if [ "$x" = "$y" ]; then
+                found=true
+            else
+                found=false
+            fi
         done
-        unset IFS
         if ! $found; then
-            if ! $ifexists || [ -d "$x" ]; then
-                if [ ! "$PATH" ]; then
-                    PATH="$x"
-                elif $start; then
-                    PATH="$x:$PATH"
-                else
-                    PATH="$PATH:$x"
-                fi
+            if [ ! "$newpath" ]; then
+                newpath="$y"
+            else
+                newpath="$newpath:$y"
+            fi
+        fi
+    done
+
+    unset IFS
+    PATH="$newpath"
+    for x in "$@"; do
+        if ! $ifexists || [ -d "$x" ]; then
+            if [ ! "$PATH" ]; then
+                PATH="$x"
+            elif $end; then
+                PATH="$PATH:$x"
+            else
+                PATH="$x:$PATH"
             fi
         fi
     done