axfer: add a sub-command to print list of PCMs/devices

Original aplay implementation has a feature to output two types of list;
devices and PCMs. The list of devices is a result to query sound card and
pcm component structured maintained in kernel land. The list of PCMs is a
result to parse runtime configuration files in alsa-lib. Entries in the
former list is corresponding to ALSA PCM character device
('/dev/snd/pcm%uC%uD[p|c]'), while entries in the latter list includes
some 'virtual' instances in application runtime.

This commit adds an implementation for the above functionality. This is
executed by taking 'list' sub-command. A 'device' option has the same
effect as '--list-devices' and '-L' of aplay. A 'pcm' option has the same
effect as '--list-pcms' and '-l' of aplay. In both cases, an additional
option is required for stream direction. Below is examples of new command
system for this sub-command.

$ axfer list device -C (= arecord --list-devices)
$ axfer list pcm -P    (= aplay -l)

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

diff --git a/axfer/Makefile.am b/axfer/Makefile.am
index b48b9c57afb76378640da410b38d80119f7bf5fc..4e37b92f3cf0a3fedc996c787abf518b2392d2d8 100644 (file)
--- a/axfer/Makefile.am
+++ b/axfer/Makefile.am
@@ -20,4 +20,5 @@ noinst_HEADERS = \
 axfer_SOURCES = \
        misc.h \
        subcmd.h \
-       main.c
+       main.c \
+       subcmd-list.c

diff --git a/axfer/main.c b/axfer/main.c
index 1e929411224f156c412e6159e7cb546041f40028..c9cf104adce4e1ce27b94ae2ef763c16c7c2a743 100644 (file)
--- a/axfer/main.c
+++ b/axfer/main.c
@@ -181,7 +181,7 @@ int main(int argc, char *const *argv)
        if (subcmd == SUBCMD_TRANSFER)
                printf("execute 'transfer' subcmd.\n");
        else if (subcmd == SUBCMD_LIST)
-               printf("execute 'list' subcmd.\n");
+               err = subcmd_list(argc, argv, direction);
        else if (subcmd == SUBCMD_VERSION)
                print_version(argv[0]);
        else

diff --git a/axfer/subcmd-list.c b/axfer/subcmd-list.c
new file mode 100644 (file)
index 0000000..f4fd18b
--- /dev/null
+++ b/axfer/subcmd-list.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// subcmd-list.c - operations for list sub command.
+//
+// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
+//
+// Licensed under the terms of the GNU General Public License, version 2.
+
+#include "subcmd.h"
+#include "misc.h"
+
+#include <getopt.h>
+
+static int dump_device(snd_ctl_t *handle, const char *id, const char *name,
+                      snd_pcm_stream_t direction, snd_pcm_info_t *info)
+{
+       unsigned int count;
+       int i;
+       int err;
+
+       printf("card %i: %s [%s], device %i: %s [%s]\n",
+              snd_pcm_info_get_card(info), id, name,
+              snd_pcm_info_get_device(info), snd_pcm_info_get_id(info),
+              snd_pcm_info_get_name(info));
+
+       count = snd_pcm_info_get_subdevices_count(info);
+       printf("  Subdevices: %i/%i\n",
+              snd_pcm_info_get_subdevices_avail(info), count);
+
+       for (i = 0; i < count; ++i) {
+               snd_pcm_info_set_subdevice(info, i);
+
+               err = snd_ctl_pcm_info(handle, info);
+               if (err < 0) {
+                       printf("control digital audio playback info (%i): %s",
+                              snd_pcm_info_get_card(info), snd_strerror(err));
+                       continue;
+               }
+
+               printf("  Subdevice #%i: %s\n",
+                      i, snd_pcm_info_get_subdevice_name(info));
+       }
+
+       return 0;
+}
+
+static int dump_devices(snd_ctl_t *handle, const char *id, const char *name,
+                       snd_pcm_stream_t direction)
+{
+       snd_pcm_info_t *info;
+       int device = -1;
+       int err;
+
+       err = snd_pcm_info_malloc(&info);
+       if (err < 0)
+               return err;
+
+       while (1) {
+               err = snd_ctl_pcm_next_device(handle, &device);
+               if (err < 0)
+                       break;
+               if (device < 0)
+                       break;
+
+               snd_pcm_info_set_device(info, device);
+               snd_pcm_info_set_subdevice(info, 0);
+               snd_pcm_info_set_stream(info, direction);
+               err = snd_ctl_pcm_info(handle, info);
+               if (err < 0)
+                       continue;
+
+               err = dump_device(handle, id, name, direction, info);
+               if (err < 0)
+                       break;
+       }
+
+       free(info);
+       return err;
+}
+
+static int list_devices(snd_pcm_stream_t direction)
+{
+       int card = -1;
+       char name[32];
+       snd_ctl_t *handle;
+       snd_ctl_card_info_t *info;
+       int err;
+
+       err = snd_ctl_card_info_malloc(&info);
+       if (err < 0)
+               return err;
+
+       // Not found.
+       if (snd_card_next(&card) < 0 || card < 0)
+               goto end;
+
+       printf("**** List of %s Hardware Devices ****\n",
+              snd_pcm_stream_name(direction));
+
+       while (card >= 0) {
+               sprintf(name, "hw:%d", card);
+               err = snd_ctl_open(&handle, name, 0);
+               if (err < 0) {
+                       printf("control open (%i): %s",
+                              card, snd_strerror(err));
+               } else {
+                       err = snd_ctl_card_info(handle, info);
+                       if (err < 0) {
+                               printf("control hardware info (%i): %s",
+                                      card, snd_strerror(err));
+                       } else {
+                               err = dump_devices(handle,
+                                       snd_ctl_card_info_get_id(info),
+                                       snd_ctl_card_info_get_name(info),
+                                       direction);
+                       }
+                       snd_ctl_close(handle);
+               }
+
+               if (err < 0)
+                       break;
+
+               // Go to next.
+               if (snd_card_next(&card) < 0) {
+                       printf("snd_card_next");
+                       break;
+               }
+       }
+end:
+       free(info);
+       return err;
+}
+
+static int list_pcms(snd_pcm_stream_t direction)
+{
+       static const char *const filters[] = {
+               [SND_PCM_STREAM_CAPTURE]        = "Input",
+               [SND_PCM_STREAM_PLAYBACK]       = "Output",
+       };
+       const char *filter;
+       void **hints;
+       void **n;
+       char *io;
+       char *name;
+       char *desc;
+
+       if (snd_device_name_hint(-1, "pcm", &hints) < 0)
+               return -EINVAL;
+
+       filter = filters[direction];
+
+       n = hints;
+       for (n = hints; *n != NULL; ++n) {
+               io = snd_device_name_get_hint(*n, "IOID");
+               if (io != NULL && strcmp(io, filter) != 0) {
+                       free(io);
+                       continue;
+               }
+
+               name = snd_device_name_get_hint(*n, "NAME");
+               desc = snd_device_name_get_hint(*n, "DESC");
+
+               printf("%s\n", name);
+               if (desc == NULL) {
+                       free(name);
+                       free(desc);
+                       continue;
+               }
+
+
+               printf("    ");
+               while (*desc) {
+                       if (*desc == '\n')
+                               printf("\n    ");
+                       else
+                               putchar(*desc);
+                       desc++;
+               }
+               putchar('\n');
+       }
+
+       snd_device_name_free_hint(hints);
+
+       return 0;
+}
+
+static void print_help(void)
+{
+       printf("help for list sub-command.\n");
+}
+
+int subcmd_list(int argc, char *const *argv, snd_pcm_stream_t direction)
+{
+       static const struct {
+               const char *const category;
+               int (*func)(snd_pcm_stream_t direction);
+       } ops[] = {
+               {"device",      list_devices},
+               {"pcm",         list_pcms},
+       };
+       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;
+
+       // Renewed command system.
+       if (argc > 2 && !strcmp(argv[1], "list")) {
+               for (i = 0; i < ARRAY_SIZE(ops); ++i) {
+                       if (!strcmp(ops[i].category, argv[2]))
+                               return ops[i].func(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);
+       }
+
+       print_help();
+
+       return 0;
+}

diff --git a/axfer/subcmd.h b/axfer/subcmd.h
index 470a4155a5057b1bdbab82fc83feeb68e657ad06..f78b766c742a8f8f002e72c10739d41fff9ab4e3 100644 (file)
--- a/axfer/subcmd.h
+++ b/axfer/subcmd.h
@@ -11,4 +11,6 @@
 
 #include <alsa/asoundlib.h>
 
+int subcmd_list(int argc, char *const *argv, snd_pcm_stream_t direction);
+
 #endif