[completion] _fzf_complete_COMMAND_post for post processing

e.g.

_fzf_complete_foo() {
  _fzf_complete "--multi --reverse --header-lines=3" "$@" < <(
    ls -al
  )
}

_fzf_complete_foo_post() {
  awk '{print $NF}'
}

[ -n "$BASH" ] && complete -F _fzf_complete_foo -o default -o bashdefault foo

shell/completion.bash

@@ -156,15 +156,10 @@ __fzf_generic_path_completion() {
   fi
 }
 
-_fzf_feed_fifo() (
-  rm -f "$fifo"
-  mkfifo "$fifo"
-  cat <&0 > "$fifo" &
-)
-
 _fzf_complete() {
-  local fifo cur selected trigger cmd fzf
-  fifo="${TMPDIR:-/tmp}/fzf-complete-fifo-$$"
+  local cur selected trigger cmd fzf post
+  post="$(caller 0 | awk '{print $2}')_post"
+  type -t $post > /dev/null 2>&1 || post=cat
   [ ${FZF_TMUX:-1} -eq 1 ] && fzf="fzf-tmux -d ${FZF_TMUX_HEIGHT:-40%}" || fzf="fzf"
 
   cmd=$(echo ${COMP_WORDS[0]} | sed 's/[^a-z0-9_=]/_/g')
@@ -173,12 +168,10 @@ _fzf_complete() {
   if [[ ${cur} == *"$trigger" ]]; then
     cur=${cur:0:${#cur}-${#trigger}}
 
-    _fzf_feed_fifo "$fifo"
     tput sc
-    selected=$(eval "cat '$fifo' | $fzf $FZF_COMPLETION_OPTS $1 -q '$cur'" | tr '\n' ' ')
+    selected=$(cat | $fzf $FZF_COMPLETION_OPTS $1 -q "$cur" | $post | tr '\n' ' ')
     selected=${selected% } # Strip trailing space not to repeat "-o nospace"
     tput rc
-    rm -f "$fifo"
 
     if [ -n "$selected" ]; then
       COMPREPLY=("$selected")

shell/completion.zsh

@@ -79,26 +79,20 @@ _fzf_dir_completion() {
     "" "/" ""
 }
 
-_fzf_feed_fifo() (
-  rm -f "$fifo"
-  mkfifo "$fifo"
-  cat <&0 > "$fifo" &
-)
-
 _fzf_complete() {
-  local fifo fzf_opts lbuf fzf matches
-  fifo="${TMPDIR:-/tmp}/fzf-complete-fifo-$$"
+  local fzf_opts lbuf fzf matches post
   fzf_opts=$1
   lbuf=$2
+  post="${funcstack[2]}_post"
+  type $post > /dev/null 2>&1 || post=cat
+
   [ ${FZF_TMUX:-1} -eq 1 ] && fzf="fzf-tmux -d ${FZF_TMUX_HEIGHT:-40%}" || fzf="fzf"
 
-  _fzf_feed_fifo "$fifo"
-  matches=$(cat "$fifo" | ${=fzf} ${=FZF_COMPLETION_OPTS} ${=fzf_opts} -q "${(Q)prefix}" | tr '\n' ' ')
+  matches=$(cat | ${=fzf} ${=FZF_COMPLETION_OPTS} ${=fzf_opts} -q "${(Q)prefix}" | $post | tr '\n' ' ')
   if [ -n "$matches" ]; then
     LBUFFER="$lbuf$matches"
   fi
   zle redisplay
-  rm -f "$fifo"
 }
 
 _fzf_complete_telnet() {