platform_system_core/include/cutils/properties.h

134 lines
4.6 KiB
C

/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CUTILS_PROPERTIES_H
#define __CUTILS_PROPERTIES_H
#include <sys/cdefs.h>
#include <stddef.h>
#include <sys/system_properties.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/* System properties are *small* name value pairs managed by the
** property service. If your data doesn't fit in the provided
** space it is not appropriate for a system property.
**
** WARNING: system/bionic/include/sys/system_properties.h also defines
** these, but with different names. (TODO: fix that)
*/
#define PROPERTY_KEY_MAX PROP_NAME_MAX
#define PROPERTY_VALUE_MAX PROP_VALUE_MAX
/* property_get: returns the length of the value which will never be
** greater than PROPERTY_VALUE_MAX - 1 and will always be zero terminated.
** (the length does not include the terminating zero).
**
** If the property read fails or returns an empty value, the default
** value is used (if nonnull).
*/
int property_get(const char *key, char *value, const char *default_value);
/* property_get_bool: returns the value of key coerced into a
** boolean. If the property is not set, then the default value is returned.
**
* The following is considered to be true (1):
** "1", "true", "y", "yes", "on"
**
** The following is considered to be false (0):
** "0", "false", "n", "no", "off"
**
** The conversion is whitespace-sensitive (e.g. " off" will not be false).
**
** If no property with this key is set (or the key is NULL) or the boolean
** conversion fails, the default value is returned.
**/
int8_t property_get_bool(const char *key, int8_t default_value);
/* property_get_int64: returns the value of key truncated and coerced into a
** int64_t. If the property is not set, then the default value is used.
**
** The numeric conversion is identical to strtoimax with the base inferred:
** - All digits up to the first non-digit characters are read
** - The longest consecutive prefix of digits is converted to a long
**
** Valid strings of digits are:
** - An optional sign character + or -
** - An optional prefix indicating the base (otherwise base 10 is assumed)
** -- 0 prefix is octal
** -- 0x / 0X prefix is hex
**
** Leading/trailing whitespace is ignored. Overflow/underflow will cause
** numeric conversion to fail.
**
** If no property with this key is set (or the key is NULL) or the numeric
** conversion fails, the default value is returned.
**/
int64_t property_get_int64(const char *key, int64_t default_value);
/* property_get_int32: returns the value of key truncated and coerced into an
** int32_t. If the property is not set, then the default value is used.
**
** The numeric conversion is identical to strtoimax with the base inferred:
** - All digits up to the first non-digit characters are read
** - The longest consecutive prefix of digits is converted to a long
**
** Valid strings of digits are:
** - An optional sign character + or -
** - An optional prefix indicating the base (otherwise base 10 is assumed)
** -- 0 prefix is octal
** -- 0x / 0X prefix is hex
**
** Leading/trailing whitespace is ignored. Overflow/underflow will cause
** numeric conversion to fail.
**
** If no property with this key is set (or the key is NULL) or the numeric
** conversion fails, the default value is returned.
**/
int32_t property_get_int32(const char *key, int32_t default_value);
/* property_set: returns 0 on success, < 0 on failure
*/
int property_set(const char *key, const char *value);
int property_list(void (*propfn)(const char *key, const char *value, void *cookie), void *cookie);
#if defined(__BIONIC_FORTIFY) && !defined(__clang__)
extern int __property_get_real(const char *, char *, const char *)
__asm__(__USER_LABEL_PREFIX__ "property_get");
__errordecl(__property_get_too_small_error, "property_get() called with too small of a buffer");
__BIONIC_FORTIFY_INLINE
int property_get(const char *key, char *value, const char *default_value) {
size_t bos = __bos(value);
if (bos < PROPERTY_VALUE_MAX) {
__property_get_too_small_error();
}
return __property_get_real(key, value, default_value);
}
#endif
#ifdef __cplusplus
}
#endif
#endif