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int | snd_output_stdio_open (snd_output_t **outputp, const char *file, const char *mode) |
| Creates a new output object writing to a file. More...
|
|
int | snd_output_stdio_attach (snd_output_t **outputp, FILE *fp, int _close) |
| Creates a new output object using an existing stdio FILE pointer. More...
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int | snd_output_buffer_open (snd_output_t **outputp) |
| Creates a new output object with an auto-extending memory buffer. More...
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size_t | snd_output_buffer_string (snd_output_t *output, char **buf) |
| Returns the address of the buffer of a SND_OUTPUT_BUFFER output handle. More...
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int | snd_output_close (snd_output_t *output) |
| Closes an output handle. More...
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int | snd_output_printf (snd_output_t *output, const char *format,...) |
| Writes formatted output (like fprintf(3) ) to an output handle. More...
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int | snd_output_vprintf (snd_output_t *output, const char *format, va_list args) |
| Writes formatted output (like fprintf(3) ) to an output handle. More...
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int | snd_output_puts (snd_output_t *output, const char *str) |
| Writes a string to an output handle (like fputs(3) ). More...
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int | snd_output_putc (snd_output_t *output, int c) |
| Writes a character to an output handle (like putc(3) ). More...
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int | snd_output_flush (snd_output_t *output) |
| Flushes an output handle (like fflush(3)). More...
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The output functions present an interface similar to the stdio functions on top of different underlying output destinations.
Many PCM debugging functions (snd_pcm_xxx_dump_xxx
) use such an output handle to be able to write not only to the screen but also to other destinations, e.g. to files or to memory buffers.
Internal structure for an output object.
The ALSA library uses a pointer to this structure as a handle to an output object. Applications don't access its contents directly.
Output type.
Enumerator |
---|
SND_OUTPUT_STDIO |
Output to a stdio stream.
|
SND_OUTPUT_BUFFER |
Output to a memory buffer.
|
Creates a new output object with an auto-extending memory buffer.
- Parameters
-
outputp | The function puts the pointer to the new output object at the address specified by outputp . |
- Returns
- Zero if successful, otherwise a negative error code.
size_t snd_output_buffer_string |
( |
snd_output_t * |
output, |
|
|
char ** |
buf |
|
) |
| |
Returns the address of the buffer of a SND_OUTPUT_BUFFER output handle.
- Parameters
-
output | The output handle. |
buf | The functions puts the current address of the buffer at the address specified by buf . |
- Returns
- The current size of valid data in the buffer.
The address of the buffer may become invalid when output functions or snd_output_close are called.
Closes an output handle.
- Parameters
-
output | The output handle to be closed. |
- Returns
- Zero if successful, otherwise a negative error code.
Flushes an output handle (like fflush(3)).
- Parameters
-
- Returns
- Zero if successful, otherwise
EOF
.
If the underlying destination is a stdio stream, this function calls fflush
. If the underlying destination is a memory buffer, the write position is reset to the beginning of the buffer. =
:-o
int snd_output_printf |
( |
snd_output_t * |
output, |
|
|
const char * |
format, |
|
|
|
... |
|
) |
| |
Writes formatted output (like fprintf(3)
) to an output handle.
- Parameters
-
output | The output handle. |
format | Format string in fprintf format. |
... | Other fprintf arguments. |
- Returns
- The number of characters written, or a negative error code.
Writes a character to an output handle (like putc(3)
).
- Parameters
-
output | The output handle. |
c | The character. |
- Returns
- Zero if successful, otherwise a negative error code or
EOF
.
int snd_output_puts |
( |
snd_output_t * |
output, |
|
|
const char * |
str |
|
) |
| |
Writes a string to an output handle (like fputs(3)
).
- Parameters
-
output | The output handle. |
str | Pointer to the string. |
- Returns
- Zero if successful, otherwise a negative error code or
EOF
.
int snd_output_stdio_attach |
( |
snd_output_t ** |
outputp, |
|
|
FILE * |
fp, |
|
|
int |
_close |
|
) |
| |
Creates a new output object using an existing stdio FILE
pointer.
- Parameters
-
outputp | The function puts the pointer to the new output object at the address specified by outputp . |
fp | The FILE pointer to write to. Characters are written to the file starting at the current file position. |
_close | Close flag. Set this to 1 if snd_output_close should close fp by calling fclose . |
- Returns
- Zero if successful, otherwise a negative error code.
- Examples:
- /test/latency.c, and /test/pcm.c.
int snd_output_stdio_open |
( |
snd_output_t ** |
outputp, |
|
|
const char * |
file, |
|
|
const char * |
mode |
|
) |
| |
Creates a new output object writing to a file.
- Parameters
-
outputp | The function puts the pointer to the new output object at the address specified by outputp . |
file | The name of the file to open. |
mode | The open mode, like fopen(3) . |
- Returns
- Zero if successful, otherwise a negative error code.
int snd_output_vprintf |
( |
snd_output_t * |
output, |
|
|
const char * |
format, |
|
|
va_list |
args |
|
) |
| |
Writes formatted output (like fprintf(3)
) to an output handle.
- Parameters
-
output | The output handle. |
format | Format string in fprintf format. |
args | Other fprintf arguments. |
- Returns
- The number of characters written, or a negative error code.