Strip symlinks from PATH.

Remove entries from PATH etc if they are symlinks to other entries
which already exist.  Useful on Solaris or Fedora 17+ where, for
example, /bin is a symlink to /usr/bin.

diff --git a/.profile.d/PATH.bashrc b/.profile.d/PATH.bashrc
index b27435a..38bb825 100644 (file)
--- a/.profile.d/PATH.bashrc
+++ b/.profile.d/PATH.bashrc
@@ -121,6 +121,35 @@ function makepath() {
   eval "export $newpath='$path'"
 }
 
+# Remove entries which are symlinks to other existing entries.
+function canonicalisepath() {
+  local path="$1"; shift
+  local newpath=
+
+  local JGD=$IFS
+  IFS='
+'
+
+  local dirs=$(eval echo "\$$path")
+  local check=":$dirs:"
+  for dir in ${dirs//:/
+}; do
+    if [ -L "$dir" ]; then
+      # Is this a symlink to another entry?
+      local canon=$(readlink -f "$dir" 2>/dev/null)
+      if [ -n "$canon" ]; then
+        [ "${check/:$canon:/}" = "$check" ] || continue
+      fi
+    fi
+
+    newpath="$newpath:$dir"
+  done
+
+  IFS=$JGD
+
+  eval "export $path='${newpath##:}'"
+}
+
 # Construct directory list, omitting nonexistent and undefined ones.
 dirs=
 for dir in "${SYSTEM:-@}/${ARCHITECTURE:-@}" "${SYSTEM:-@}" ""; do
@@ -141,10 +170,10 @@ for path in $PATHS; do
       [ -e "$dir" ] || continue
       makepath "$var" "$dir"
     done
+    canonicalisepath "$var"
   else
     copypath "$var" "${source#@}"
   fi
 done
 
-
-unset DIR PATHS dir dirs path var source expandpath sanitisepath copypath makepath newpath addpath
+unset DIR PATHS dir dirs path var source expandpath sanitisepath copypath makepath newpath addpath canonicalisepath