From 0976603694f0fb1bf078260317d78c6c8194b4ae Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Sat, 7 Jan 2017 20:47:37 +1300
Subject: Improvements to path()

* Move common directory argument checking into helper function
* Tolerate only one directory argument
* Show subcommand in error output
* Don't show help on failed commands, just suggest it
* (Technicality) Fix trailing-newline lossage in subshell function
---
 sh/shrc.d/path.sh | 55 +++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 39 insertions(+), 16 deletions(-)

(limited to 'sh')

diff --git a/sh/shrc.d/path.sh b/sh/shrc.d/path.sh
index 3caabbc9..23eec75b 100644
--- a/sh/shrc.d/path.sh
+++ b/sh/shrc.d/path.sh
@@ -24,10 +24,28 @@ path() {
             done
             ) ;;
 
+        # Helper function checks directory argument makes sense
+        _argcheck)
+            shift
+            if [ "$#" -gt 2 ] ; then
+                printf >&2 'path(): %s: too many arguments\n' "$1"
+                return 2
+            fi
+            case $2 in
+                *:*)
+                    printf >&2 'path(): %s: %s contains colon\n' "$@"
+                    return 2
+                    ;;
+            esac
+            return 0
+            ;;
+
         # Add a directory at the start of $PATH
         insert)
+            [ "$#" -eq 2 ] || set -- "$1" "$PWD"
+            path _argcheck "$@" || return
             if path check "$2" ; then
-                printf >&2 'path(): %s already in PATH\n' "$2"
+                printf >&2 'path(): %s: %s already in PATH\n' "$@"
                 return 1
             fi
             PATH=${2}${PATH:+:"$PATH"}
@@ -35,8 +53,10 @@ path() {
 
         # Add a directory to the end of $PATH
         append)
+            [ "$#" -eq 2 ] || set -- "$1" "$PWD"
+            path _argcheck "$@" || return
             if path check "$2" ; then
-                printf >&2 'path(): %s already in PATH\n' "$2"
+                printf >&2 'path(): %s: %s already in PATH\n' "$@"
                 return 1
             fi
             PATH=${PATH:+"$PATH":}${2}
@@ -44,21 +64,25 @@ path() {
 
         # Remove a directory from $PATH
         remove)
+            [ "$#" -eq 2 ] || set -- "$1" "$PWD"
+            path _argcheck "$@" || return
             if ! path check "$2" ; then
-                printf >&2 'path(): %s not in PATH\n' "$2"
+                printf >&2 'path(): %s: %s not in PATH\n' "$@"
                 return 1
             fi
             PATH=$(
                 path=:$PATH:
                 path=${path%%:"$2":*}:${path#*:"$2":}
                 path=${path#:}
-                path=${path%:}
-                printf '%s\n' "$path"
+                printf '%s:' "$path"
             )
+            PATH=${PATH%%:}
             ;;
 
         # Check whether a directory is in PATH
         check)
+            path _argcheck "$@" || return
+            [ "$#" -eq 2 ] || set -- "$1" "$PWD"
             case :$PATH: in
                 *:"$2":*) return 0 ;;
             esac
@@ -73,23 +97,22 @@ path(): Manage contents of PATH variable
 USAGE:
   path [list]
     Print the current directories in PATH, one per line (default command)
-  path insert DIR
-    Add a directory to the front of PATH
-  path append DIR
-    Add a directory to the end of PATH
-  path remove DIR
-    Remove directory from PATH
-  path check DIR
-    Return whether DIR is a component of PATH
+  path insert [DIR]
+    Add directory DIR (default $PWD) to the front of PATH
+  path append [DIR]
+    Add directory DIR (default $PWD) to the end of PATH
+  path remove [DIR]
+    Remove directory DIR (default $PWD) from PATH
+  path check [DIR]
+    Return whether directory DIR (default $PWD) is a component of PATH
   path help
-    Print this help message (also done if command not found)
+    Print this help message
 EOF
             ;;
 
         # Command not found
         *)
-            printf >&2 'path(): Unknown command\n'
-            path help >&2
+            printf >&2 'path(): %s: Unknown command (try "help")\n' "$1"
             return 2
             ;;
     esac
-- 
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