First version of configuration helpers

configure.in

@@ -43,6 +43,6 @@ AC_OUTPUT(Makefile doc/Makefile include/Makefile src/Makefile \
           src/control/Makefile src/mixer/Makefile src/pcm/Makefile \
 	  src/pcm/plugin/Makefile src/rawmidi/Makefile src/timer/Makefile \
           src/hwdep/Makefile src/seq/Makefile src/instr/Makefile \
-          src/compat/Makefile \
+          src/compat/Makefile src/conf/Makefile \
           test/Makefile utils/Makefile \
           utils/alsa-lib.spec)

include/Makefile.am

@@ -4,7 +4,7 @@ sysinclude_HEADERS = asoundlib.h
 # This is the order they will be concatenated into asoundlib.h!
 #
 header_files=header.h version.h error.h control.h mixer.h pcm.h rawmidi.h \
-             timer.h hwdep.h seq.h seqmid.h conv.h instr.h footer.h
+             timer.h hwdep.h seq.h seqmid.h conv.h instr.h conf.h footer.h
 
 noinst_HEADERS=$(header_files) search.h
 

include/conf.h

@@ -0,0 +1,57 @@
+
+typedef enum {
+        SND_CONFIG_TYPE_INTEGER,
+        SND_CONFIG_TYPE_REAL,
+        SND_CONFIG_TYPE_STRING,
+	SND_CONFIG_TYPE_COMPOUND,
+} snd_config_type_t;
+
+typedef struct snd_config snd_config_t;
+
+struct snd_config {
+	char *id;
+	snd_config_type_t type;
+	union {
+		long integer;
+		char *string;
+		double real;
+		struct {
+			struct list_head fields;
+			int join;
+		} compound;
+	} u;
+	struct list_head list;
+	snd_config_t *father;
+};
+
+
+int snd_config_load(snd_config_t **config, FILE *fp);
+int snd_config_save(snd_config_t *config, FILE *fp);
+
+int snd_config_search(snd_config_t *config, char *key, snd_config_t **result);
+
+int snd_config_add(snd_config_t *config, snd_config_t *leaf);
+int snd_config_delete(snd_config_t *config);
+
+int snd_config_make(snd_config_t **config, char *key,
+		    snd_config_type_t type);
+
+int snd_config_integer_set(snd_config_t *config, long value);
+int snd_config_real_set(snd_config_t *config, double value);
+int snd_config_string_set(snd_config_t *config, char *value);
+int snd_config_integer_get(snd_config_t *config, long *value);
+int snd_config_real_get(snd_config_t *config, double *value);
+int snd_config_string_get(snd_config_t *config, char **value);
+
+/* One argument: long, double or char* */
+int snd_config_set(snd_config_t *config, ...);
+int snd_config_get(snd_config_t *config, void *);
+
+typedef struct list_head *snd_config_iterator_t;
+
+#define snd_config_foreach(iterator, node) \
+	assert((node)->type == SND_CONFIG_TYPE_COMPOUND); \
+	for (iterator = (node)->u.compound.fields.next; iterator != &(node)->u.compound.fields; iterator = iterator->next)
+
+#define snd_config_entry(iterator) list_entry(iterator, snd_config_t, list)
+

include/header.h

@@ -1,6 +1,7 @@
 /*
  *  Application interface library for the ALSA driver
  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
+ *                   Abramo Bagnara <abramo@alsa-project.org>
  *
  *
  *   This library is free software; you can redistribute it and/or modify

src/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS=control mixer pcm rawmidi timer hwdep seq instr compat
+SUBDIRS=control mixer pcm rawmidi timer hwdep seq instr compat conf
 COMPATNUM=@LIBTOOL_VERSION_INFO@
 
 lib_LTLIBRARIES = libasound.la

src/conf/Makefile.am

@@ -0,0 +1,8 @@
+EXTRA_LTLIBRARIES = libconf.la
+
+libconf_la_SOURCES = conf.c
+
+all: libconf.la
+
+
+INCLUDES=-I$(top_srcdir)/include

src/conf/conf.c

@@ -0,0 +1,863 @@
+/*
+ *  Configuration helper functions
+ *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdarg.h>
+#include "asoundlib.h"
+#include "list.h"
+
+typedef struct {
+	FILE *fp;
+	unsigned int line, column;
+	int unget;
+	int ch;
+	enum {
+		UNTERMINATED_STRING = -1,
+		UNTERMINATED_QUOTE = -2,
+		UNEXPECTED_CHAR = -3,
+		UNEXPECTED_EOF = -4,
+	} error;
+} input_t;
+
+static int get_char(input_t *input)
+{
+	int c;
+	if (input->unget) {
+		input->unget = 0;
+		return input->ch;
+	}
+	c = getc(input->fp);
+	switch (c) {
+	case '\n':
+		input->column = 0;
+		input->line++;
+		break;
+	case '\t':
+		input->column += 8 - input->column % 8;
+		break;
+	case EOF:
+		break;
+	default:
+		input->column++;
+		break;
+	}
+	return c;
+}
+
+static void unget_char(int c, input_t *input)
+{
+	assert(!input->unget);
+	input->ch = c;
+	input->unget = 1;
+}
+
+static int get_char_skip_comments(input_t *input)
+{
+	int c;
+	while (1) {
+		c = get_char(input);
+		if (c != '#')
+			break;
+		while (1) {
+			c = get_char(input);
+			if (c == EOF)
+				return c;
+			if (c == '\n')
+				break;
+		}
+	}
+	return c;
+}
+			
+static int get_nonwhite(input_t *input)
+{
+	int c;
+	while (1) {
+		c = get_char_skip_comments(input);
+		switch (c) {
+		case ' ':
+		case '\f':
+		case '\t':
+		case '\n':
+		case '\r':
+			break;
+		default:
+			return c;
+		}
+	}
+}
+
+static int get_quotedchar(input_t *input)
+{
+	int c;
+	c = get_char(input);
+	switch (c) {
+	case 'n':
+		return '\n';
+	case 't':
+		return '\t';
+	case 'v':
+		return '\v';
+	case 'b':
+		return '\b';
+	case 'r':
+		return '\r';
+	case 'f':
+		return '\f';
+	case '0' ... '7':
+	{
+		int num = c - '0';
+		int i = 1;
+		do {
+			c = get_char(input);
+			if (c < '0' || c > '7') {
+				unget_char(c, input);
+				break;
+			}
+			num = num * 8 + c - '0';
+			i++;
+		} while (i < 3);
+		return num;
+	}
+	default:
+		return c;
+	}
+}
+
+static int get_freestring(char **string, input_t *input)
+{
+	const size_t bufsize = 256;
+	char _buf[bufsize];
+	char *buf = _buf;
+	size_t alloc = bufsize;
+	size_t idx = 0;
+	int c;
+	while (1) {
+		c = get_char(input);
+		switch (c) {
+		case ' ':
+		case '\f':
+		case '\t':
+		case '\n':
+		case '\r':
+		case EOF:
+		case '.':
+		case '=':
+		case '{':
+		case '}':
+		case ',':
+		case ';':
+		case '\'':
+		case '"':
+		case '\\':
+		case '#':
+		{
+			char *s = malloc(idx + 1);
+			unget_char(c, input);
+			memcpy(s, buf, idx);
+			s[idx] = '\0';
+			*string = s;
+			return 0;
+		}
+		default:
+			break;
+		}
+		if (idx >= alloc) {
+			size_t old_alloc = alloc;
+			alloc *= 2;
+			if (old_alloc == bufsize) {
+				buf = malloc(alloc);
+				memcpy(buf, _buf, old_alloc);
+			} else
+				buf = realloc(buf, alloc);
+		}
+		buf[idx++] = c;
+	}
+	return 0;
+}
+			
+static int get_delimstring(char **string, int delim, input_t *input)
+{
+	const size_t bufsize = 256;
+	char _buf[bufsize];
+	char *buf = _buf;
+	size_t alloc = bufsize;
+	size_t idx = 0;
+	int c;
+	while (1) {
+		c = get_char(input);
+		switch (c) {
+		case EOF:
+			input->error = UNTERMINATED_STRING;
+			return -1;
+		case '\\':
+			c = get_quotedchar(input);
+			if (c < 0) {
+				input->error = UNTERMINATED_QUOTE;
+				return -1;
+			}
+			break;
+		default:
+			if (c == delim) {
+				char *s = malloc(idx + 1);
+				memcpy(s, buf, idx);
+				s[idx] = '\0';
+				*string = s;
+				return 0;
+			}
+		}
+		if (idx >= alloc) {
+			size_t old_alloc = alloc;
+			alloc *= 2;
+			if (old_alloc == bufsize) {
+				buf = malloc(alloc);
+				memcpy(buf, _buf, old_alloc);
+			} else
+				buf = realloc(buf, alloc);
+		}
+		buf[idx++] = c;
+	}
+	return 0;
+}
+
+/* Return 1 for free string, 0 for delimited string */
+static int get_string(char **string, input_t *input)
+{
+	int c = get_nonwhite(input);
+	int err;
+	switch (c) {
+	case EOF:
+		input->error = UNEXPECTED_EOF;
+		return -1;
+	case '=':
+#if 0
+	  	/* I'm not sure to want unnamed fields */
+		*string = 0;
+		return 0;
+#endif
+	case '.':
+	case '{':
+	case '}':
+	case ',':
+	case ';':
+		input->error = UNEXPECTED_CHAR;
+		return -1;
+	case '\'':
+	case '"':
+		err = get_delimstring(string, c, input);
+		if (err < 0)
+			return err;
+		return 0;
+	default:
+		unget_char(c, input);
+		err = get_freestring(string, input);
+		if (err < 0)
+			return err;
+		return 1;
+	}
+}
+
+static int _snd_config_make(snd_config_t **config, char *id,
+			    snd_config_type_t type)
+{
+	snd_config_t *n;
+	n = calloc(1, sizeof(*n));
+	if (n == NULL) {
+		if (id)
+			free(id);
+		return -ENOMEM;
+	}
+	n->id = id;
+	n->type = type;
+	if (type == SND_CONFIG_TYPE_COMPOUND)
+		INIT_LIST_HEAD(&n->u.compound.fields);
+	*config = n;
+	return 0;
+}
+	
+
+static int _snd_config_make_add(snd_config_t **config, char *id,
+				snd_config_type_t type, snd_config_t *father)
+{
+	snd_config_t *n;
+	int err;
+	assert(father->type == SND_CONFIG_TYPE_COMPOUND);
+	err = _snd_config_make(&n, id, type);
+	if (err < 0)
+		return err;
+	n->father = father;
+	list_add_tail(&n->list, &father->u.compound.fields);
+	*config = n;
+	return 0;
+}
+
+static int _snd_config_search(snd_config_t *config, char *id, int len, snd_config_t **result)
+{
+	snd_config_iterator_t i;
+	snd_config_foreach(i, config) {
+		snd_config_t *n = snd_config_entry(i);
+		if (len < 0) {
+			if (strcmp(n->id, id) == 0) {
+				*result = n;
+				return 0;
+			}
+		} else {
+			if (strlen(n->id) != (size_t) len)
+				continue;
+			if (memcmp(n->id, id, len) == 0) {
+				*result = n;
+				return 0;
+			}
+		}
+	}
+	return -ENOENT;
+}
+
+static int parse_defs(snd_config_t *father, input_t *input);
+
+static int parse_def(snd_config_t *father, input_t *input)
+{
+	char *id;
+	int c;
+	int err;
+	snd_config_t *n;
+	enum {MERGE, NOCREATE, REMOVE} mode;
+	while (1) {
+		c = get_nonwhite(input);
+		switch (c) {
+		case '?':
+			mode = NOCREATE;
+			break;
+		case '!':
+			mode = REMOVE;
+			break;
+		default:
+			mode = MERGE;
+			unget_char(c, input);
+		}
+		err = get_string(&id, input);
+		if (err < 0)
+			return err;
+		c = get_nonwhite(input);
+		if (c != '.')
+			break;
+		if (_snd_config_search(father, id, -1, &n) == 0) {
+			if (mode != REMOVE) {
+				if (n->type != SND_CONFIG_TYPE_COMPOUND)
+					return -EINVAL;
+				n->u.compound.join = 1;
+				father = n;
+				free(id);
+				continue;
+			}
+			snd_config_delete(n);
+		}
+		if (mode == NOCREATE) {
+			free(id);
+			return -ENOENT;
+		}
+		err = _snd_config_make_add(&n, id, SND_CONFIG_TYPE_COMPOUND, father);
+		if (err < 0)
+			return err;
+		n->u.compound.join = 1;
+		father = n;
+	}
+	if (c == '=' )
+		c = get_nonwhite(input);
+	if (_snd_config_search(father, id, -1, &n) == 0) {
+		if (mode == REMOVE) {
+			snd_config_delete(n);
+			n = NULL;
+		}
+		else
+			free(id);
+	} else {
+		n = NULL;
+		if (mode == NOCREATE) {
+			free(id);
+			return -ENOENT;
+		}
+	}
+	switch (c) {
+	case '{':
+	{
+		if (n) {
+			if (n->type != SND_CONFIG_TYPE_COMPOUND)
+				return -EINVAL;
+		} else {
+			err = _snd_config_make_add(&n, id, SND_CONFIG_TYPE_COMPOUND, father);
+			if (err < 0)
+				return err;
+		}
+		err = parse_defs(n, input);
+		if (err < 0) {
+			snd_config_delete(n);
+			return err;
+		}
+		c = get_nonwhite(input);
+		if (c != '}') {
+			snd_config_delete(n);
+			input->error = UNEXPECTED_CHAR;
+			return -1;
+		}
+		break;
+	}
+	default:
+	{
+		char *s;
+		unget_char(c, input);
+		err = get_string(&s, input);
+		if (err < 0)
+			return err;
+		if (s[0] >= '0' && s[0] <= '9') {
+			char *ptr;
+			long i;
+			errno = 0;
+			i = strtol(s, &ptr, 0);
+			if (*ptr == '.' || errno != 0) {
+				double r;
+				errno = 0;
+				r = strtod(s, &ptr);
+				if (errno == 0) {
+					free(s);
+					if (n) {
+						if (n->type != SND_CONFIG_TYPE_REAL)
+							return -EINVAL;
+					} else {
+						err = _snd_config_make_add(&n, id, SND_CONFIG_TYPE_REAL, father);
+						if (err < 0)
+							return err;
+					}
+					n->u.real = r;
+					break;
+				}
+			} else if (*ptr == '\0') {
+				free(s);
+				if (n) {
+					if (n->type != SND_CONFIG_TYPE_INTEGER)
+						return -EINVAL;
+				} else {
+					err = _snd_config_make_add(&n, id, SND_CONFIG_TYPE_INTEGER, father);
+					if (err < 0)
+						return err;
+				}
+				n->u.integer = i;
+				break;
+			}
+		}
+		if (n) {
+			if (n->type != SND_CONFIG_TYPE_STRING) {
+				free(s);
+				return -EINVAL;
+			}
+		} else {
+			err = _snd_config_make_add(&n, id, SND_CONFIG_TYPE_STRING, father);
+			if (err < 0)
+				return err;
+		}
+		if (n->u.string)
+			free(n->u.string);
+		n->u.string = s;
+	}
+	}
+	c = get_nonwhite(input);
+	switch (c) {
+	case ';':
+	case ',':
+		break;
+	default:
+		unget_char(c, input);
+	}
+	return err;
+}
+		
+static int parse_defs(snd_config_t *father, input_t *input)
+{
+	while (1) {
+		int c = get_nonwhite(input);
+		int err;
+		if (c == EOF)
+			return 0;
+		unget_char(c, input);
+		if (c == '}')
+			return 0;
+		err = parse_def(father, input);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+
+int snd_config_load(snd_config_t **config, FILE *fp)
+{
+	int err;
+	input_t input;
+	snd_config_t *c;
+	assert(config && fp);
+	err = _snd_config_make(&c, 0, SND_CONFIG_TYPE_COMPOUND);
+	if (err < 0)
+		return err;
+	input.fp = fp;
+	input.line = 1;
+	input.column = 0;
+	input.unget = 0;
+	err = parse_defs(c, &input);
+	if (err < 0) {
+		snd_config_delete(c);
+		return err;
+	}
+	if (get_char(&input) != EOF) {
+		snd_config_delete(c);
+		return -1;
+	}
+	*config = c;
+	return 0;
+}
+
+int snd_config_add(snd_config_t *config, snd_config_t *leaf)
+{
+	snd_config_iterator_t i;
+	assert(config && leaf);
+	snd_config_foreach(i, config) {
+		snd_config_t *n = snd_config_entry(i);
+		if (strcmp(leaf->id, n->id) == 0)
+			return -EEXIST;
+	}
+	leaf->father = config;
+	list_add_tail(&leaf->list, &config->u.compound.fields);
+	return 0;
+}
+
+int snd_config_delete(snd_config_t *config)
+{
+	assert(config);
+	switch (config->type) {
+	case SND_CONFIG_TYPE_COMPOUND:
+	{
+		int err;
+		struct list_head *i;
+		i = config->u.compound.fields.next;
+		while (i != &config->u.compound.fields) {
+			struct list_head *nexti = i->next;
+			snd_config_t *leaf = snd_config_entry(i);
+			err = snd_config_delete(leaf);
+			if (err < 0)
+				return err;
+			i = nexti;
+		}
+		break;
+	}
+	case SND_CONFIG_TYPE_STRING:
+		if (config->u.string)
+			free(config->u.string);
+		break;
+	default:
+		break;
+	}
+	if (config->father)
+		list_del(&config->list);
+	return 0;
+}
+
+int snd_config_make(snd_config_t **config, char *id,
+		    snd_config_type_t type)
+{
+	char *id1;
+	assert(config);
+	if (id) {
+		id1 = strdup(id);
+		if (!id1)
+			return -ENOMEM;
+	} else
+		id1 = NULL;
+	return _snd_config_make(config, id, type);
+}
+
+int snd_config_integer_set(snd_config_t *config, long value)
+{
+	assert(config->type == SND_CONFIG_TYPE_INTEGER);
+	config->u.integer = value;
+	return 0;
+}
+
+int snd_config_real_set(snd_config_t *config, double value)
+{
+	assert(config->type == SND_CONFIG_TYPE_REAL);
+	config->u.real = value;
+	return 0;
+}
+
+int snd_config_string_set(snd_config_t *config, char *value)
+{
+	assert(config);
+	assert(config->type == SND_CONFIG_TYPE_INTEGER);
+	if (config->u.string)
+		free(config->u.string);
+	config->u.string = strdup(value);
+	if (!config->u.string)
+		return -ENOMEM;
+	return 0;
+}
+
+int snd_config_set(snd_config_t *config, ...)
+{
+	va_list arg;
+	va_start(arg, config);
+	assert(config);
+	switch (config->type) {
+	case SND_CONFIG_TYPE_INTEGER:
+		config->u.integer = va_arg(arg, long);
+		break;
+	case SND_CONFIG_TYPE_REAL:
+		config->u.real = va_arg(arg, double);
+		break;
+	case SND_CONFIG_TYPE_STRING:
+		config->u.string = va_arg(arg, char *);
+		break;
+	default:
+		assert(0);
+		return -EINVAL;
+	}
+	va_end(arg);
+	return 0;
+}
+
+int snd_config_integer_get(snd_config_t *config, long *ptr)
+{
+	assert(config && ptr);
+	assert(config->type == SND_CONFIG_TYPE_INTEGER);
+	*ptr = config->u.integer;
+	return 0;
+}
+
+int snd_config_real_get(snd_config_t *config, double *ptr)
+{
+	assert(config && ptr);
+	assert(config->type == SND_CONFIG_TYPE_REAL);
+	*ptr = config->u.real;
+	return 0;
+}
+
+int snd_config_string_get(snd_config_t *config, char **ptr)
+{
+	assert(config && ptr);
+	assert(config->type == SND_CONFIG_TYPE_INTEGER);
+	*ptr = config->u.string;
+	return 0;
+}
+
+int snd_config_get(snd_config_t *config, void *ptr)
+{
+	assert(config && ptr);
+	switch (config->type) {
+	case SND_CONFIG_TYPE_INTEGER:
+		* (long*) ptr = config->u.integer;
+		break;
+	case SND_CONFIG_TYPE_REAL:
+		* (double*) ptr = config->u.real;
+		break;
+	case SND_CONFIG_TYPE_STRING:
+		* (char **) ptr = config->u.string;
+		break;
+	default:
+		assert(0);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+void quoted_print(char *str, FILE *fp)
+{
+	int quote = 0;
+	unsigned char *p = str;
+ loop:
+	switch (*p) {
+	case 0:
+		break;
+	case 1 ... 31:
+	case 127 ... 255:
+	case ' ':
+	case '=':
+	case '.':
+	case '{':
+	case '}':
+	case ';':
+	case ',':
+	case '\'':
+	case '"':
+		quote = 1;
+		break;
+	default:
+		p++;
+		goto loop;
+	}
+	if (!quote) {
+		fputs(str, fp);
+		return;
+	}
+	putc('\'', fp);
+	p = str;
+	while (*p) {
+		int c;
+		c = *p;
+		switch (c) {
+		case '\n':
+			putc('\\', fp);
+			putc('n', fp);
+			break;
+		case '\t':
+			putc('\\', fp);
+			putc('t', fp);
+			break;
+		case '\v':
+			putc('\\', fp);
+			putc('v', fp);
+			break;
+		case '\b':
+			putc('\\', fp);
+			putc('b', fp);
+			break;
+		case '\r':
+			putc('\\', fp);
+			putc('r', fp);
+			break;
+		case '\f':
+			putc('\\', fp);
+			putc('f', fp);
+			break;
+		case '\'':
+			putc('\\', fp);
+			putc(c, fp);
+			break;
+		case 32 ... '\'' - 1:
+		case '\'' + 1 ... 126:
+			putc(c, fp);
+			break;
+		default:
+			fprintf(fp, "\\%04o", c);
+			break;
+		}
+		p++;
+	}
+	putc('\'', fp);
+}
+
+static int _snd_config_save_leaves(snd_config_t *config, FILE *fp, unsigned int level, unsigned int joins);
+
+static int _snd_config_save_leaf(snd_config_t *n, FILE *fp, 
+				 unsigned int level)
+{
+	int err;
+	unsigned int k;
+	switch (n->type) {
+	case SND_CONFIG_TYPE_INTEGER:
+		printf("%ld", n->u.integer);
+		break;
+	case SND_CONFIG_TYPE_REAL:
+		printf("%16g", n->u.real);
+		break;
+	case SND_CONFIG_TYPE_STRING:
+		quoted_print(n->u.string, fp);
+		break;
+	case SND_CONFIG_TYPE_COMPOUND:
+		putc('{', fp);
+		putc('\n', fp);
+		err = _snd_config_save_leaves(n, fp, level + 1, 0);
+		if (err < 0)
+			return err;
+		for (k = 0; k < level; ++k) {
+			putc('\t', fp);
+		}
+		putc('}', fp);
+		break;
+	}
+	return 0;
+}
+
+static void id_print(snd_config_t *n, FILE *fp, unsigned int joins)
+{
+	if (joins > 0) {
+		assert(n->father);
+		id_print(n->father, fp, joins - 1);
+		putc('.', fp);
+	}
+	quoted_print(n->id, fp);
+}
+
+static int _snd_config_save_leaves(snd_config_t *config, FILE *fp, unsigned int level, unsigned int joins)
+{
+	unsigned int k;
+	int err;
+	snd_config_iterator_t i;
+	assert(config && fp);
+	snd_config_foreach(i, config) {
+		snd_config_t *n = snd_config_entry(i);
+		if (n->type == SND_CONFIG_TYPE_COMPOUND &&
+		    n->u.compound.join) {
+			err = _snd_config_save_leaves(n, fp, level, joins + 1);
+			if (err < 0)
+				return err;
+			continue;
+		}
+		for (k = 0; k < level; ++k) {
+			putc('\t', fp);
+		}
+		id_print(n, fp, joins);
+		putc(' ', fp);
+		putc('=', fp);
+		putc(' ', fp);
+		err = _snd_config_save_leaf(n, fp, level);
+		if (err < 0)
+			return err;
+		putc(';', fp);
+		putc('\n', fp);
+	}
+	return 0;
+}
+
+int snd_config_save(snd_config_t *config, FILE *fp)
+{
+	assert(config && fp);
+	return _snd_config_save_leaves(config, fp, 0, 0);
+}
+
+int snd_config_search(snd_config_t *config, char *key, snd_config_t **result)
+{
+	assert(config && key && result);
+	while (1) {
+		snd_config_t *n;
+		int err;
+		char *p = strchr(key, '.');
+		if (p) {
+			err = _snd_config_search(config, key, p - key, &n);
+			if (err < 0)
+				return err;
+			if (n->type != SND_CONFIG_TYPE_COMPOUND)
+				return -EINVAL;
+			config = n;
+			key = p + 1;
+		} else
+			return _snd_config_search(config, key, -1, result);
+	}
+}
+