PATCH: _canonical_paths

[Clint Adams <clint@xxxxxxx>]

Utility function meant to be used in _mount, from R. Ramkumar.

Index: Completion/Unix/Type/_canonical_paths
===================================================================
RCS file: Completion/Unix/Type/_canonical_paths
diff -N Completion/Unix/Type/_canonical_paths
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ Completion/Unix/Type/_canonical_paths	28 May 2006 18:31:25 -0000
@@ -0,0 +1,94 @@
+#autoload
+
+# This completion function completes all paths given to it, and also tries to
+# offer completions which point to the same file as one of the paths given
+# (relative path when an absolute path is given, and vice versa; when ..'s are
+# present in the word to be completed, and some paths got from symlinks.
+
+# Usage: _canonical_paths [-A var] [-N] [-MJV12nfX] tag desc paths...
+
+# -A, if specified, takes the paths from the array variable specified. Paths can
+# also be specified on the command line as shown above. -N, if specified,
+# prevents canonicalizing the paths given before using them for completion, in
+# case they are already so. `tag' and `desc' arguments are well, obvious :) In
+# addition, the options -M, -J, -V, -1, -2, -n, -F, -X are passed to compadd.
+
+local __index
+typeset -a __gopts __opts
+
+zparseopts -D -a __gopts M: J: V: 1 2 n F: X: A:=__opts N=__opts
+
+: ${1:=canonical-paths} ${2:=path}
+
+__index=$__opts[(I)-A]
+(( $__index )) && set -- $@ ${(P)__opts[__index+1]}
+
+local expl ret=1 tag=$1 desc=$2
+
+shift 2
+
+if (( ! $+commands[readlink] )); then
+  _wanted "$tag" expl "$desc" compadd $__gopts $@ && ret=0
+  return ret
+fi
+
+typeset -a matches files
+
+if (( $__opts[(I)-N] )); then
+  files=($@)
+else
+  for __index in $@; do
+    files+=$(readlink -qf $__index)
+  done
+fi
+
+_canonical_paths_add_paths () {
+  local origpref=$1 expref rltrim curpref canpref subdir
+  [[ $2 != add ]] && matches=()
+  expref=${~origpref}
+  [[ $origpref == (|*/). ]] && rltrim=.
+  curpref=${${expref%$rltrim}:-./}
+  canpref=$(readlink -qf $curpref)
+  if [[ $? -eq 0 ]]; then
+    [[ $curpref == */ && $canpref == *[^/] ]] && canpref+=/
+    canpref+=$rltrim
+    [[ $expref == *[^/] && $canpref == */ ]] && origpref+=/
+    matches+=(${${(M)files:#$canpref*}/$canpref/$origpref})
+  fi
+  for subdir in $expref?*(@); do
+    _canonical_paths_add_paths ${subdir/$expref/$origpref} add
+  done
+}
+
+local base=$PREFIX
+typeset -i blimit
+
+_canonical_paths_add_paths $base
+
+if [[ -z $base ]]; then
+  _canonical_paths_add_paths / add
+elif [[ $base == ..(/.(|.))#(|/) ]]; then
+
+  # This style controls how many parent directory links (..) to chase searching
+  # for possible completions. The default is 8. Note that this chasing is
+  # triggered only when the user enters atleast a .. and the path completed
+  # contains only . or .. components. A value of 0 turns off .. link chasing
+  # altogether.
+
+  zstyle -s ":completion:${curcontext}:$tag" \
+    canonical-paths-back-limit blimit || blimit=8
+
+  if [[ $base != */ ]]; then
+    [[ $base != *.. ]] && base+=.
+    base+=/
+  fi
+  until [[ $base.. -ef $base || blimit -le 0 ]]; do
+    base+=../
+    _canonical_paths_add_paths $base add
+    blimit+=-1
+  done
+fi
+
+_wanted "$tag" expl "$desc" compadd $__gopts -Q -U -a matches && ret=0
+
+return ret