axfer: apply refactoring to list subcommand for backward compatibility to aplay(1)

This commit splits option parser for backward compatibility to aplay(1)
in list subcommand. Supported operations are listed in local enumeration.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/axfer/subcmd-list.c b/axfer/subcmd-list.c
index f4fd18b36e853a18dfa163c0be452b3bd3dd33f4..0876e074c2c5afc90dc948e915df63a7cc0b3826 100644 (file)
--- a/axfer/subcmd-list.c
+++ b/axfer/subcmd-list.c
@@ -10,6 +10,13 @@
 #include "misc.h"
 
 #include <getopt.h>
+#include <stdbool.h>
+
+enum list_op {
+       LIST_OP_DEVICE = 0,
+       LIST_OP_PCM,
+       LIST_OP_HELP,
+};
 
 static int dump_device(snd_ctl_t *handle, const char *id, const char *name,
                       snd_pcm_stream_t direction, snd_pcm_info_t *info)
@@ -189,6 +196,35 @@ static void print_help(void)
        printf("help for list sub-command.\n");
 }
 
+// Backward compatibility to aplay(1).
+static bool decide_operation(int argc, char *const *argv, enum list_op *op)
+{
+       static const char *s_opts = "hlL";
+       static const struct option l_opts[] = {
+               {"list-devices",        0, NULL, 'l'},
+               {"list-pcms",           0, NULL, 'L'},
+               {NULL,                  0, NULL, 0}
+       };
+
+       optind = 0;
+       opterr = 0;
+       while (1) {
+               int c = getopt_long(argc, argv, s_opts, l_opts, NULL);
+               if (c < 0)
+                       break;
+               if (c == 'l') {
+                       *op = LIST_OP_DEVICE;
+                       return true;
+               }
+               if (c == 'L') {
+                       *op = LIST_OP_PCM;
+                       return true;
+               }
+       }
+
+       return false;
+}
+
 int subcmd_list(int argc, char *const *argv, snd_pcm_stream_t direction)
 {
        static const struct {
@@ -198,14 +234,9 @@ int subcmd_list(int argc, char *const *argv, snd_pcm_stream_t direction)
                {"device",      list_devices},
                {"pcm",         list_pcms},
        };
+       enum list_op op;
        int i;
-       static const char *s_opts = "hlL";
-       static const struct option l_opts[] = {
-               {"list-devices",        0, NULL, 'l'},
-               {"list-pcms",           0, NULL, 'L'},
-               {NULL,                  0, NULL, 0}
-       };
-       int c;
+       int err;
 
        // Renewed command system.
        if (argc > 2 && !strcmp(argv[1], "list")) {
@@ -215,20 +246,17 @@ int subcmd_list(int argc, char *const *argv, snd_pcm_stream_t direction)
                }
        }
 
-       // Original command system.
-       optind = 0;
-       opterr = 0;
-       while (1) {
-               c = getopt_long(argc, argv, s_opts, l_opts, NULL);
-               if (c < 0)
-                       break;
-               if (c == 'l')
-                       return list_devices(direction);
-               if (c == 'L')
-                       return list_pcms(direction);
+       if (!decide_operation(argc, argv, &op)) {
+               err = -EINVAL;
+               op = LIST_OP_HELP;
        }
 
-       print_help();
+       if (op == LIST_OP_DEVICE)
+               err = list_devices(direction);
+       else if (op == LIST_OP_PCM)
+               err = list_pcms(direction);
+       else
+               print_help();
 
-       return 0;
+       return err;
 }