fix(portinstall): use awk and _comp_compgen to filter completions

Author: akinomyoga

completions/portinstall

@@ -7,24 +7,20 @@ _comp_cmd_portinstall()
 
     [[ $prev == -l || $prev == -L || $prev == -o ]] && return
 
-    local portsdir indexfile
-    local -a COMPREPLY2
-
-    portsdir=${PORTSDIR:-/usr/ports}/
+    local -x portsdir=${PORTSDIR:-/usr/ports}/
 
     # First try INDEX-5
-    indexfile=$portsdir/INDEX-5
+    local indexfile=$portsdir/INDEX-5
     # Then INDEX if INDEX-5 does not exist or system is not FreeBSD 5.x
     [[ ${OSTYPE%.*} == freebsd5 && -f $indexfile ]] ||
         indexfile=$portsdir/INDEX
     [[ -f $indexfile && -r $indexfile ]] || return
 
-    COMPREPLY=($(command grep -E "^$cur" 2>/dev/null <"$indexfile" |
-        cut -d'|' -f1))
-    COMPREPLY2=($(command grep -E "^[^\|]+\|$portsdir$cur" 2>/dev/null \
-        <"$indexfile" | cut -d'|' -f2))
-    COMPREPLY2=(${COMPREPLY2[@]#$portsdir})
-    COMPREPLY+=("${COMPREPLY2[@]}")
+    _comp_compgen_split -l -- "$(awk -F '|' '
+        BEGIN { portsdir = ENVIRON["portsdir"]; len = length(portsdir) }
+        { print $1 }
+        substr($2, 1, len) == portsdir { print substr($2, len + 1) }
+        ' "$indexfile")"
 
 } &&
     complete -F _comp_cmd_portinstall -o dirnames portinstall