From b4b144c3f8aa98a26b9a59c204ec0d5b4619ef72 Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Thu, 25 May 2017 18:21:23 +1200
Subject: Shorter/saner implementation for bd()

Avoids subshell mess and consequent trailing-space workaround
---
 sh/shrc.d/bd.sh | 85 ++++++++++++++++++++-------------------------------------
 1 file changed, 29 insertions(+), 56 deletions(-)

diff --git a/sh/shrc.d/bd.sh b/sh/shrc.d/bd.sh
index bf64a9aa..02da6773 100644
--- a/sh/shrc.d/bd.sh
+++ b/sh/shrc.d/bd.sh
@@ -3,68 +3,41 @@ bd() {
 
     # Check argument count
     if [ "$#" -gt 1 ] ; then
-        printf >&2 'bd(): Too many arguments'
+        printf >&2 'bd(): Too many arguments\n'
         return 2
     fi
 
-    # Set positional parameters to an option terminator and what will hopefully
-    # end up being a target directory
-    set -- "$(
+    # Look at argument given
+    case $1 in
 
-        # The requested pattern is the first argument, defaulting to just the
-        # parent directory
-        req=${1:-..}
+        # If it has a leading slash or is . or .., don't touch the arguments
+        /*|.|..) ;;
 
-        # Strip trailing slashes if a trailing slash is not the whole pattern
-        [ "$req" = / ] || req=${req%/}
+        # Otherwise, we'll try to find a matching ancestor and then shift the
+        # initial request off the argument list
+        *)
 
-        # What to do now depends on the request
-        case $req in
+            # Push the current directory onto the stack
+            set -- "$1" "$PWD"
 
-            # Just go straight to the root or dot directories if asked
-            (/|.|..)
-                dirname=$req
-                ;;
-
-            # Anything with a leading / needs to anchor to the start of the
-            # path. A strange request though. Why not just use cd?
-            (/*)
-                dirname=$req
-                case $PWD in
-                    ("$dirname"/*) ;;
-                    (*) dirname='' ;;
+            # Keep chopping at the current directory until it's empty or it
+            # matches the request
+            while [ -n "$2" ] ; do
+                set -- "$1" "${2%/*}"
+                case $2 in
+                    (*/"$1") break ;;
                 esac
-                ;;
-
-            # In all other cases, iterate through the PWD to find a match, or
-            # whittle the target down to an empty string trying
-            (*)
-                dirname=$PWD
-                while [ -n "$dirname" ] ; do
-                    dirname=${dirname%/*}
-                    case $dirname in
-                        (*/"$req") break ;;
-                    esac
-                done
-                ;;
-        esac
-
-        # Check we have a target after all that
-        if [ -z "$dirname" ] ; then
-            printf >&2 'bd(): Directory name not in path\n'
-            exit 1
-        fi
-
-        # Print the target with trailing slash to work around newline stripping
-        printf '%s/' "${dirname%/}"
-    )"
-
-    # Remove trailing slash
-    set -- "${1%/}"
-
-    # If the subshell printed nothing, return with failure
-    [ -n "$1" ] || return
-
-    # Try to change into the determined directory
-    command cd -- "$@"
+            done
+
+            # If the first argument ended up empty, we have no match
+            if [ -z "$2" ] ; then
+                printf >&2 'bd(): No match\n'
+                return 1
+            fi
+            shift
+            ;;
+    esac
+
+    # We have a match; try and change into it
+    command cd -- "$1"
 }
-- 
cgit v1.2.3