Add parse-cmd-dsl

README.md

@@ -92,6 +92,15 @@ Arguments are handled as follows:
    expecting a file – use `psub-echo` or `psub-format`, which don’t
    actually call an external program.)
 
+### Parsing the `cmd` DSL
+
+You can use the `cmd` DSL in your own programs with `cmd:parse-cmd-dsl`. This takes a list of arguments and returns two values: a fully-tokenized list of command arguments and a list of keyword arguments, both suitable for passsing to `uiop:launch-program`.
+
+``` lisp
+(parse-cmd-dsl '("echo 'hello world' > myfile"))
+=> ("echo" "hello world"), (:OUTPUT "myfile")
+```
+
 ## The external program’s working directory
 
 Cmd is designed with multi-threaded programs in mind. It always runs

cmd.lisp

@@ -28,6 +28,7 @@
   (:export
    :cmd :$cmd :cmd? :cmd! :cmd&
    :sh :$sh :sh? :sh! :sh&
+   :parse-cmd-dsl
    :with-cmd-dir
    :with-working-directory
    :current-directory
@@ -555,6 +556,18 @@ Except that it doesn't actually launch an external program."
   (receive (argv kwargs) (argv+kwargs args)
     (make 'cmd :argv argv :kwargs kwargs)))
 
+(defun parse-cmd-dsl (command)
+  "Parse COMMAND like `cmd' does.
+Returns two values: the fully tokenized command, and a list of
+redirection arguments (in the format expected by
+`uiop:launch-program').
+
+This can be used to write your own functions that support the `cmd' DSL."
+  (check-type command list)
+  (let ((cmd (parse-cmd command)))
+    (values (flatten-string-tokens (cmd-argv cmd))
+            (flatten-string-tokens (cmd-kwargs cmd)))))
+
 (defun split-pipeline (args)
   "Split ARGS into two values: the last command in the pipeline, and any previous commands."
   (let* ((args (parse-cmd-args args))

test.lisp

@@ -2,13 +2,14 @@
   (:use :cl :cmd/cmd :fiveam :alexandria :serapeum)
   ;; Internal symbols.
   (:import-from
-    :cmd/cmd
-    :expand-keyword-aliases
-    :split-cmd
-    :flatten-string-tokens
-    :kill-process-group
-    :wrap-cmd-env
-    :vterm-terminal)
+   :cmd/cmd
+   :parse-cmd-dsl
+   :expand-keyword-aliases
+   :flatten-string-tokens
+   :kill-process-group
+   :split-cmd
+   :vterm-terminal
+   :wrap-cmd-env)
   (:import-from :uiop :os-unix-p :subprocess-error)
   (:export :run-tests))
 (in-package :cmd/test)
@@ -239,3 +240,10 @@
     (is (string= "a file" ($cmd "ls" #p"foo bar")))
     (locally (declare (notinline $cmd))
       (is (string= "a file" ($cmd "ls" #p"foo bar"))))))
+
+(test parse-cmd-dsl
+  (is (equal
+       (multiple-value-list
+        (parse-cmd-dsl '("echo 'hello world' > myfile")))
+       '(("echo" "hello world")
+         (:output "myfile")))))