mcron: Handle command line arguments in C with argp

'argp' is a convenient and maintainable way to parse command line arguments.
Guile doesn't offer an equivalent of this, so the command line handling has
been moved to C.

* src/mcron.c (parse_args, parse_opt): New functions.
(inner_main): Call 'parse_args'.
* src/mcron/scripts/mcron.scm (show-help, %options): Delete.
(main): Remove command line handling.

1 files changed, 27 insertions, 60 deletions

diff --git a/src/mcron/scripts/mcron.scm b/src/mcron/scripts/mcron.scm
index b6c7729..588734b 100644
--- a/src/mcron/scripts/mcron.scm
+++ b/src/mcron/scripts/mcron.scm
@@ -25,34 +25,6 @@
   #:use-module (mcron vixie-specification)
   #:export (main))
 
-(define (show-help)
-  (display "Usage: mcron [OPTIONS] [FILES]
-Run an mcron process according to the specifications in the FILES (`-' for
-standard input), or use all the files in ~/.config/cron (or the
-deprecated ~/.cron) with .guile or .vixie extensions.
-
-  -v, --version             Display version
-  -h, --help                Display this help message
-  -sN, --schedule[=]N       Display the next N jobs that will be run by mcron
-  -d, --daemon              Immediately detach the program from the terminal
-                              and run as a daemon process
-  -i, --stdin=(guile|vixie) Format of data passed as standard input or
-                              file arguments (default guile)")
-  (newline)
-  (show-package-information))
-
-(define %options
-  `((schedule (single-char #\s) (value #t)
-              (predicate ,(λ (str) (string->number str))))
-    (daemon   (single-char #\d) (value #f))
-    (noetc    (single-char #\n) (value #f))
-    (stdin    (single-char #\i) (value #t)
-              (predicate ,(λ (val)
-                            (or (string=? val "guile")
-                                (string=? val "vixie")))))
-    (version  (single-char #\v) (value #f))
-    (help     (single-char #\h) (value #f))))
-
 (define process-user-file
   (let ((guile-regexp (make-regexp "\\.gui(le)?$"))
         (vixie-regexp (make-regexp "\\.vix(ie)?$")))
@@ -102,35 +74,30 @@ $XDG_CONFIG_HOME is not defined uses ~/.config/cron instead)."
 ;;; Entry point.
 ;;;
 
-(define* (main #:optional (args (command-line)))
-  (let ((opts (parse-args args %options)))
-    (when config-debug
-      (debug-enable 'backtrace))
-    (cond ((option-ref opts 'help #f)
-           (show-help)
-           (exit 0))
-          ((option-ref opts 'version #f)
-           (show-version "mcron")
-           (exit 0))
-          (else
-           (%process-files (option-ref opts '() '())
-                           (option-ref opts 'stdin "guile"))
-           (cond ((option-ref opts 'schedule #f) ;display jobs schedule
-                  => (λ (count)
-                       (display (get-schedule (max 1 (string->number count))))
-                       (exit 0)))
-                 ((option-ref opts 'daemon #f) ;run mcron as a daemon
-                  (case (primitive-fork)
-                    ((0)  (setsid))
-                    (else (exit 0)))))
-           ;; Forever execute the 'run-job-loop', and when it drops out (can
-           ;; only be because a message has come in on the socket) we process
-           ;; the socket request before restarting the loop again.
-           (catch-mcron-error
-            (let ((fdes-list '()))
-              (while #t
-                (run-job-loop fdes-list)
-                ;; we can also drop out of run-job-loop because of a SIGCHLD,
-                ;; so must test FDES-LIST.
-                (unless (null? fdes-list)
-                  (process-update-request fdes-list)))))))))
+(define* (main #:optional (opts '()))
+  (when config-debug
+    (debug-enable 'backtrace))
+
+  (%process-files (or (assq-ref opts 'files) '())
+                  (if (assq-ref opts 'vixie) "vixie" "guile"))
+
+  (cond ((assq-ref opts 'schedule) ;display jobs schedule
+         => (λ (count)
+              (display (get-schedule (max 1 count)))
+              (exit 0)))
+        ((assq-ref opts 'daemon) ;run mcron as a daemon
+         (case (primitive-fork)
+           ((0)  (setsid))
+           (else (exit 0)))))
+
+  ;; Forever execute the 'run-job-loop', and when it drops out (can
+  ;; only be because a message has come in on the socket) we process
+  ;; the socket request before restarting the loop again.
+  (catch-mcron-error
+   (let ((fdes-list '()))
+     (while #t
+       (run-job-loop fdes-list)
+       ;; we can also drop out of run-job-loop because of a SIGCHLD,
+       ;; so must test FDES-LIST.
+       (unless (null? fdes-list)
+         (process-update-request fdes-list))))))