Re: [dev] [dmenu] dmenu_run improvements

On Sun, Jul 24, 2011 at 12:35:19PM +0800, lolilolicon wrote:
> dmenu_run doesn't really run the user input as a shell command line.
> For instance, run dmenu_run from a terminal, then in the menu type:
>
> echo hello\ world
>
> The terminal output is "hello\ world" instead of "hello world".
>
> `eval' solves the problem, but when it comes to eval, I can't really
> be sure, so please point out the possible errors/risks.

Assuredly the least of the evils in this script -- the eval is
necessary. More noteworthy is the parsing of ls here, which can easily
be refactored out and still be /bin/sh compat. It also explodes on first
run, and then there's the needless invocation of mkdir every time the
cache is regenerated. suckless could suck a lot less at shell scripting.
dmenu_run has gone through several iterations of bad and worse.

d

#!/bin/sh

CACHE=${XDG_CACHE_HOME:-"$HOME/.cache"}/dmenu_run
IFS=:
LC_COLLLATE=C

gencache() {
  lsx $PATH | sort -u >"$CACHE"
}

if [ ! -e "$CACHE" ]; then
  mkdir -p "${CACHE%/*}"
  gencache
fi

for path in $PATH; do
  if [ "$path" -nt "$CACHE" ]; then
    gencache
    break
  fi
done
unset IFS

cmd=$(dmenu "$@" < "$CACHE") && eval exec "$cmd"

>
> `LC_ALL=C' is for sort.
>
> diff -up a/dmenu_run b/dmenu_run
> --- a/dmenu_run 1970-01-01 00:00:00.000000000 +0000
> +++ b/dmenu_run 1970-01-01 00:00:00.000000000 +0000
> @@ -1,9 +1,9 @@
> #!/bin/sh
> CACHE=${XDG_CACHE_HOME:-"$HOME/.cache"}/dmenu_run
> (
> - IFS=:
> + IFS=: LC_ALL=C
> if test "`ls -dt $PATH "$CACHE" 2> /dev/null | sed 1q`" != "$CACHE"; then
> mkdir -p "`dirname "$CACHE"`" && lsx $PATH | sort -u > "$CACHE"
> fi
> )
> -cmd=`dmenu "$@" < "$CACHE"` && exec $cmd
> +cmd=`dmenu "$@" < "$CACHE"` && eval exec "$cmd"
>
Received on Sun Jul 24 2011 - 07:34:30 CEST