Add a -script switch to the fifo to cater for grep/make use cases

Avoid the brittle `exit; %arg{@}` trick

rc/tools/fifo.kak

@@ -1,12 +1,14 @@
 provide-module fifo %{
 
 define-command -params .. -docstring %{
-    fifo [-name <buffer-name>] [-scroll] [--] <command>...: run command in a fifo buffer
+    fifo [-name <name>] [-scroll] [-script <script>] [--] <args>...: run command in a fifo buffer
+    if <script> is used, eval it with <args> as '$@', else pass arguments directly to the shell
 } fifo %{ evaluate-commands %sh{
     name='*fifo*'
     while true; do
         case "$1" in
             "-scroll") scroll="-scroll"; shift ;;
+            "-script") script="$2"; shift 2 ;;
             "-name") name="$2"; shift 2 ;;
             "--") shift; break ;;
             *) break ;;
@@ -14,7 +16,11 @@ define-command -params .. -docstring %{
     done
     output=$(mktemp -d "${TMPDIR:-/tmp}"/kak-fifo.XXXXXXXX)/fifo
     mkfifo ${output}
-    ( eval "$@" > ${output} 2>&1 & ) > /dev/null 2>&1 < /dev/null
+    if [ -n "$script" ]; then
+        ( eval "$script" > ${output} 2>&1 & ) > /dev/null 2>&1 < /dev/null
+    else
+        ( "$@" > ${output} 2>&1 & ) > /dev/null 2>&1 < /dev/null
+    fi
 
     printf %s\\n "
             edit! -fifo ${output} ${scroll} ${name}

rc/tools/grep.kak

@@ -12,8 +12,7 @@ define-command -params .. -docstring %{
     Passing no argument will perform a literal-string grep for the current selection
 } grep %{
     evaluate-commands -try-client %opt{toolsclient} %{
-        fifo -name *grep* %{
-            shift 2
+        fifo -name *grep* -script %{
             trap - INT QUIT
             if [ $# -eq 0 ]; then
                 case "$kak_opt_grepcmd" in
@@ -29,7 +28,7 @@ define-command -params .. -docstring %{
                 esac
             fi
             $kak_opt_grepcmd "$@" 2>&1 | tr -d '\r'
-        } 'exit;' %arg{@} # pass arguments for "$@" above, exit to avoid evaluating them
+        } %arg{@}
         set-option buffer filetype grep
         set-option buffer jump_current_line 0
     }

rc/tools/make.kak

@@ -13,11 +13,10 @@ define-command -params .. -docstring %{
     All the optional arguments are forwarded to the make utility
 } make %{
     evaluate-commands -try-client %opt{toolsclient} %{
-        fifo -scroll -name *make* %{
-            shift 2
+        fifo -scroll -name *make* -script %{
             trap - INT QUIT
             $kak_opt_makecmd "$@"
-        } 'exit;' %arg{@} # pass arguments for "$@" above, exit to avoid evaluating them
+        } %arg{@} # pass arguments for "$@" above, exit to avoid evaluating them
         set-option buffer filetype make
         set-option buffer jump_current_line 0
     }