From cbbec36d4403dbed6d61232e86b5d4995c8da1fe Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Sat, 27 May 2017 22:52:40 +1200
Subject: More error-resistant sd()

---
 sh/shrc.d/hgrep.sh |  6 ++--
 sh/shrc.d/pmd.sh   |  2 +-
 sh/shrc.d/sd.sh    | 86 ++++++++++++++++++++++++++++++++++++------------------
 3 files changed, 62 insertions(+), 32 deletions(-)

(limited to 'sh')

diff --git a/sh/shrc.d/hgrep.sh b/sh/shrc.d/hgrep.sh
index 1c4c3ec5..fe297ab3 100644
--- a/sh/shrc.d/hgrep.sh
+++ b/sh/shrc.d/hgrep.sh
@@ -6,11 +6,11 @@
 hgrep() {
     if [ "$#" -eq 0 ] ; then
         printf >&2 'hgrep(): Need a pattern\n'
-        exit 2
+        return 2
     fi
-    if ! [ -n "$HISTFILE" ] ; then
+    if [ -z "$HISTFILE" ] ; then
         printf >&2 'hgrep(): No HISTFILE\n'
-        exit 2
+        return 2
     fi
     grep "$@" "$HISTFILE"
 }
diff --git a/sh/shrc.d/pmd.sh b/sh/shrc.d/pmd.sh
index c96a50bd..4b0cd5bd 100644
--- a/sh/shrc.d/pmd.sh
+++ b/sh/shrc.d/pmd.sh
@@ -1,6 +1,6 @@
 # Print the marked directory
 pmd() {
-    if ! [ -n "$PMD" ] ; then
+    if [ -z "$PMD" ] ; then
         printf >&2 'pmd(): Mark not set\n'
         return 1
     fi
diff --git a/sh/shrc.d/sd.sh b/sh/shrc.d/sd.sh
index af82b67e..8b12c170 100644
--- a/sh/shrc.d/sd.sh
+++ b/sh/shrc.d/sd.sh
@@ -41,45 +41,75 @@ sd() {
     # Read sole optional argument
     case $1 in
 
-        # If blank, get a full list of directories at this level; include
-        # dotfiles, but not the . and .. entries, using glob tricks to avoid
-        # Bash ruining things with `dotglob`
+        # Slashes aren't allowed
+        */*)
+            printf >&2 'bd(): Illegal slash\n'
+            return 2
+            ;;
+
+        # If blank, we try to find if there's just one sibling, and change to
+        # that if so
         '')
+            # First a special case: root dir
+            case $PWD in
+                *[!/]*) ;;
+                *)
+                    printf >&2 'sd(): No siblings\n'
+                    return 1
+                    ;;
+            esac
+
+            # Get a full list of directories at this level; include dotfiles,
+            # but not the . and .. entries, using glob tricks to avoid Bash
+            # ruining things with `dotglob`
             set -- ../[!.]*/
             [ -e "$1" ] || shift
             set -- ../.[!.]*/ "$@"
             [ -e "$1" ] || shift
             set -- ../..?*/ "$@"
             [ -e "$1" ] || shift
-            ;;
 
-        # If not, get that directory, and the current one; shift it off if it
-        # doesn't exist
-        *)
-            set -- ../"${1%/}"/ ../"${PWD##*/}"/
-            [ -e "$1" ] || shift
-            ;;
-    esac
+            # Check the number of matches
+            case $# in
 
-    # We should now have two parameters: the current directory and the matched
-    # sibling
-    case $# in
-        2) ;;
-        0|1)
-            printf >&2 'sd(): No match\n'
-            return 1
-            ;;
-        *)
-            printf >&2 'sd(): Multiple matches\n'
-            return 1
+                # One match? Must be $PWD, so no siblings--throw in 0 just in
+                # case, but that Shouldn't Happen (TM)
+                0|1)
+                    printf >&2 'sd(): No siblings\n'
+                    return 1
+                    ;;
+
+                # Two matches; hopefully just one sibling, but which is it?
+                2)
+
+                    # Push PWD onto the stack, strip trailing slashes
+                    set -- "$1" "$2" "$PWD"
+                    while : ; do
+                        case $3 in
+                            */) set -- "$1" "$2" "${3%/}" ;;
+                            *) break ;;
+                        esac
+                    done
+
+                    # Pick whichever of our two parameters doesn't look like
+                    # PWD as our sole parameter
+                    case $1 in
+                        ../"${3##*/}"/) set -- "$2" ;;
+                        *) set -- "$1" ;;
+                    esac
+                    ;;
+
+                # Anything else? Multiple siblings--user will need to specify
+                *)
+                    printf >&2 'sd(): Multiple siblings\n'
+                    return 1
+                    ;;
+            esac
             ;;
-    esac
 
-    # Find which of these two is not the current directory and set that as our
-    # sole parameter
-    case $1 in
-        ../"${PWD##*/}"/) set -- "$2" ;;
-        *) set -- "$1" ;;
+        # If not, simply set our target to that directory, and let `cd` do the
+        # complaining if it doesn't exist
+        *) set -- ../"$1" ;;
     esac
 
     # Try and change into the first parameter
-- 
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