SDL  2.0
SDL_audiodev.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../SDL_internal.h"
22 
23 /* Get the name of the audio device we use for output */
24 
25 #if SDL_AUDIO_DRIVER_NETBSD || SDL_AUDIO_DRIVER_OSS || SDL_AUDIO_DRIVER_SUNAUDIO
26 
27 #include <fcntl.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <unistd.h> /* For close() */
31 
32 #include "SDL_stdinc.h"
33 #include "SDL_audiodev_c.h"
34 
35 #ifndef _PATH_DEV_DSP
36 #if defined(__NETBSD__) || defined(__OPENBSD__)
37 #define _PATH_DEV_DSP "/dev/audio"
38 #else
39 #define _PATH_DEV_DSP "/dev/dsp"
40 #endif
41 #endif
42 #ifndef _PATH_DEV_DSP24
43 #define _PATH_DEV_DSP24 "/dev/sound/dsp"
44 #endif
45 #ifndef _PATH_DEV_AUDIO
46 #define _PATH_DEV_AUDIO "/dev/audio"
47 #endif
48 
49 static void
50 test_device(const int iscapture, const char *fname, int flags, int (*test) (int fd))
51 {
52  struct stat sb;
53  if ((stat(fname, &sb) == 0) && (S_ISCHR(sb.st_mode))) {
54  const int audio_fd = open(fname, flags, 0);
55  if (audio_fd >= 0) {
56  const int okay = test(audio_fd);
57  close(audio_fd);
58  if (okay) {
59  static size_t dummyhandle = 0;
60  dummyhandle++;
61  SDL_assert(dummyhandle != 0);
62  SDL_AddAudioDevice(iscapture, fname, (void *) dummyhandle);
63  }
64  }
65  }
66 }
67 
68 static int
69 test_stub(int fd)
70 {
71  return 1;
72 }
73 
74 static void
75 SDL_EnumUnixAudioDevices_Internal(const int iscapture, const int classic, int (*test)(int))
76 {
77  const int flags = iscapture ? OPEN_FLAGS_INPUT : OPEN_FLAGS_OUTPUT;
78  const char *audiodev;
79  char audiopath[1024];
80 
81  if (test == NULL)
82  test = test_stub;
83 
84  /* Figure out what our audio device is */
85  if (((audiodev = SDL_getenv("SDL_PATH_DSP")) == NULL) &&
86  ((audiodev = SDL_getenv("AUDIODEV")) == NULL)) {
87  if (classic) {
88  audiodev = _PATH_DEV_AUDIO;
89  } else {
90  struct stat sb;
91 
92  /* Added support for /dev/sound/\* in Linux 2.4 */
93  if (((stat("/dev/sound", &sb) == 0) && S_ISDIR(sb.st_mode))
94  && ((stat(_PATH_DEV_DSP24, &sb) == 0)
95  && S_ISCHR(sb.st_mode))) {
96  audiodev = _PATH_DEV_DSP24;
97  } else {
98  audiodev = _PATH_DEV_DSP;
99  }
100  }
101  }
102  test_device(iscapture, audiodev, flags, test);
103 
104  if (SDL_strlen(audiodev) < (sizeof(audiopath) - 3)) {
105  int instance = 0;
106  while (instance <= 64) {
107  SDL_snprintf(audiopath, SDL_arraysize(audiopath),
108  "%s%d", audiodev, instance);
109  instance++;
110  test_device(iscapture, audiopath, flags, test);
111  }
112  }
113 }
114 
115 void
116 SDL_EnumUnixAudioDevices(const int classic, int (*test)(int))
117 {
118  SDL_EnumUnixAudioDevices_Internal(SDL_TRUE, classic, test);
119  SDL_EnumUnixAudioDevices_Internal(SDL_FALSE, classic, test);
120 }
121 
122 #endif /* Audio driver selection */
123 
124 /* vi: set ts=4 sw=4 expandtab: */
#define OPEN_FLAGS_INPUT
void SDL_EnumUnixAudioDevices(const int classic, int(*test)(int))
#define OPEN_FLAGS_OUTPUT
#define SDL_getenv
#define SDL_assert(condition)
Definition: SDL_assert.h:169
#define NULL
Definition: begin_code.h:164
GLbitfield flags
#define SDL_strlen
#define SDL_snprintf
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93
GLuint64 GLenum GLint fd
Definition: gl2ext.h:1508
void SDL_AddAudioDevice(const int iscapture, const char *name, void *handle)
Definition: SDL_audio.c:432