a.1 "second"
\endcode
+\section conf_mode Parsed node operation mode
+
+By default, the node operation node is 'merge+create'. It means, if
+a configuration node is not present a new one is created, otherwise
+the latest assignment is merged (if possible - type checking). The
+'merge+create' operation mode is specified with a prefix char plus (+).
+
+The operation mode 'merge' merges the node with old one (which must
+exists). Type checking is done, so string cannot be assigned to integer
+and so on. This mode is specified with a prefix char minus (-).
+
+The operation mode 'do not override' ignores a new configuration node
+if a configuration node with same name exists. This mode is specified with
+a prefix char note of interrogation (?).
+
+The operation mode 'override' always overrides the old configuration node
+with new contents. This mode is specified with a prefix char note of
+exclamation (!).
+
+\code
+!defaults.pcm.device 1
+\endcode
+
\section conf_syntax_summary Syntax summary
\code
name.1 [=] value1 [,|;]
\endcode
+\section conf_syntax_ref References
+\ref confarg
+\ref conffunc
+\ref confhooks
*/
card $CARD
\endcode
+\section confarg_usage Usage
+
+Arguments are replaced with real values when the key contains part after
+colon (:). For example, all these names for PCM interface gives same result:
+
+\code
+hw:0,1
+hw:CARD=0,DEV=1
+hw:{CARD 0 DEV 1}
+plug:"hw:0,1"
+plug:{SLAVE="hw:{CARD 0 DEV 1}"}
+\endcode
+
+As you see, the argument can be specified by order or by name. Note that
+arguments closed into braces are parsed in same way like configuration files,
+but with the override method by default.
+
\section confarg_example Example
\code
*/
+/*! \page confhooks Configuration - hooks
+
+<P>The hook extension in the ALSA library allows expanding of configuration
+nodes at run-time lookup. The presence of a hook is determined with a @hooks
+compound node.</P>
+
+<P>The example definition a hook which loads two configuration files at beginning:</P>
+
+\code
+@hooks [
+ {
+ func load
+ files [
+ "/etc/asound.conf"
+ "~/.asoundrc"
+ ]
+ errors false
+ }
+]
+\endcode
+
+\section confhooks_ref Function reference
+
+<UL>
+ <LI>The function load - snd_config_hook_load() - loads and parses the given
+ configuration files.
+ <LI>The function load_for_all_cards - snd_config_hook_load_for_all_cards() -
+ loads and parses the given configuration files for all installed soundcards.
+ The driver name (type of soundcard) is passed in the private configuration
+ node.
+</UL>
+
+*/
+
#include <stdarg.h>
#include <wordexp.h>
break;
while (1) {
c = get_char(input);
- if (c == EOF)
- return LOCAL_UNEXPECTED_EOF;
+ if (c < 0)
+ return c;
if (c == '\n')
break;
}
while (1) {
c = get_char(input);
if (c < 0) {
- if (buf != _buf)
+ if (c == LOCAL_UNEXPECTED_EOF) {
+ char *s = malloc(idx + 1);
+ if (!s)
+ return -ENOMEM;
+ memcpy(s, buf, idx);
+ s[idx] = '\0';
+ *string = s;
+ c = 0;
+ }
+ if (alloc > bufsize)
free(buf);
return c;
}
return 0;
}
-static int parse_defs(snd_config_t *father, input_t *input, int skip);
-static int parse_array_defs(snd_config_t *farther, input_t *input, int skip);
+static int parse_defs(snd_config_t *father, input_t *input, int skip, int override);
+static int parse_array_defs(snd_config_t *farther, input_t *input, int skip, int override);
-static int parse_array_def(snd_config_t *father, input_t *input, int idx, int skip)
+static int parse_array_def(snd_config_t *father, input_t *input, int idx, int skip, int override)
{
char static_id[12], *id = NULL;
int c;
}
}
if (c == '{') {
- err = parse_defs(n, input, skip);
+ err = parse_defs(n, input, skip, override);
endchr = '}';
} else {
- err = parse_array_defs(n, input, skip);
+ err = parse_array_defs(n, input, skip, override);
endchr = ']';
}
c = get_nonwhite(input);
return err;
}
-static int parse_array_defs(snd_config_t *father, input_t *input, int skip)
+static int parse_array_defs(snd_config_t *father, input_t *input, int skip, int override)
{
int idx = 0;
while (1) {
unget_char(c, input);
if (c == ']')
return 0;
- err = parse_array_def(father, input, idx++, skip);
+ err = parse_array_def(father, input, idx++, skip, override);
if (err < 0)
return err;
}
return 0;
}
-static int parse_def(snd_config_t *father, input_t *input, int skip)
+static int parse_def(snd_config_t *father, input_t *input, int skip, int override)
{
char *id = NULL;
int c;
if (c < 0)
return c;
switch (c) {
+ case '+':
+ mode = MERGE_CREATE;
+ break;
+ case '-':
+ mode = MERGE;
+ break;
case '?':
mode = DONT_OVERRIDE;
break;
mode = OVERRIDE;
break;
default:
- mode = MERGE_CREATE;
+ mode = !override ? MERGE_CREATE : OVERRIDE;
unget_char(c, input);
}
err = get_string(&id, 1, input);
}
}
if (c == '{') {
- err = parse_defs(n, input, skip);
+ err = parse_defs(n, input, skip, override);
endchr = '}';
} else {
- err = parse_array_defs(n, input, skip);
+ err = parse_array_defs(n, input, skip, override);
endchr = ']';
}
c = get_nonwhite(input);
return err;
}
-static int parse_defs(snd_config_t *father, input_t *input, int skip)
+static int parse_defs(snd_config_t *father, input_t *input, int skip, int override)
{
int c, err;
while (1) {
unget_char(c, input);
if (c == '}')
return 0;
- err = parse_def(father, input, skip);
+ err = parse_def(father, input, skip, override);
if (err < 0)
return err;
}
return _snd_config_make(config, 0, SND_CONFIG_TYPE_COMPOUND);
}
-/**
- * \brief Load a config tree
- * \param config Config top node handle
- * \param in Input handle
- * \return 0 on success otherwise a negative error code
- */
-int snd_config_load(snd_config_t *config, snd_input_t *in)
+static int snd_config_load1(snd_config_t *config, snd_input_t *in, int override)
{
int err;
input_t input;
fd->next = NULL;
input.current = fd;
input.unget = 0;
- err = parse_defs(config, &input, 0);
+ err = parse_defs(config, &input, 0, override);
fd = input.current;
if (err < 0) {
const char *str;
}
/**
+ * \brief Load a config tree
+ * \param config Config top node handle
+ * \param in Input handle
+ * \return 0 on success otherwise a negative error code
+ */
+int snd_config_load(snd_config_t *config, snd_input_t *in)
+{
+ return snd_config_load1(config, in, 0);
+}
+
+/**
+ * \brief Load a config tree and override existing configuration nodes
+ * \param config Config top node handle
+ * \param in Input handle
+ * \return 0 on success otherwise a negative error code
+ */
+int snd_config_load_override(snd_config_t *config, snd_input_t *in)
+{
+ return snd_config_load1(config, in, 1);
+}
+
+/**
* \brief Add a leaf to a config compound node
* \param father Config compound node handle
* \param leaf Leaf config node handle
err = snd_input_buffer_open(&input, str + 1, len - 1);
if (err < 0)
return err;
- err = snd_config_load(subs, input);
+ err = snd_config_load_override(subs, input);
snd_input_close(input);
if (err < 0)
return err;
/**
* \brief Search a definition inside a config tree using alias and expand hooks and arguments
* \param config Config node handle
- * \param base Key base (or NULL)
+ * \param base Implicit key base (or NULL - none)
* \param key Key suffix
* \param result Pointer to expanded found node
* \return 0 on success otherwise a negative error code
key[args - name - 1] = '\0';
} else {
key = (char *) name;
- }
- err = snd_config_search_alias_hooks(config, NULL, key, &conf);
- if (err < 0)
- err = snd_config_search_alias_hooks(config, base, key, &conf);
+ }
+ /*
+ * if key contains dot (.), the implicit base is ignored
+ * and the key starts from root given by the 'config' parameter
+ */
+ err = snd_config_search_alias_hooks(config, strchr(key, '.') ? NULL : base, key, &conf);
if (err < 0)
return err;
return snd_config_expand(conf, config, args, NULL, result);
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