Initial Contribution

libc/include/sys/system_properties.h

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _INCLUDE_SYS_SYSTEM_PROPERTIES_H
+#define _INCLUDE_SYS_SYSTEM_PROPERTIES_H
+
+typedef struct prop_info prop_info;
+
+#define PROP_NAME_MAX   32
+#define PROP_VALUE_MAX  92
+
+/* Look up a system property by name, copying its value and a
+** \0 terminator to the provided pointer.  The total bytes
+** copied will be no greater than PROP_VALUE_MAX.  Returns
+** the string length of the value.  A property that is not
+** defined is identical to a property with a length 0 value.
+*/
+int __system_property_get(const char *name, char *value);
+
+/* Return a pointer to the system property named name, if it
+** exists, or NULL if there is no such property.  Use 
+** __system_property_read() to obtain the string value from
+** the returned prop_info pointer.
+**
+** It is safe to cache the prop_info pointer to avoid future
+** lookups.  These returned pointers will remain valid for
+** the lifetime of the system.
+*/
+const prop_info *__system_property_find(const char *name);
+
+/* Read the value of a system property.  Returns the length
+** of the value.  Copies the value and \0 terminator into
+** the provided value pointer.  Total length (including
+** terminator) will be no greater that PROP_VALUE_MAX.
+**
+** If name is nonzero, up to PROP_NAME_MAX bytes will be
+** copied into the provided name pointer.  The name will
+** be \0 terminated.
+*/
+int __system_property_read(const prop_info *pi, char *name, char *value);
+
+/* Return a prop_info for the nth system property, or NULL if 
+** there is no nth property.  Use __system_property_read() to
+** read the value of this property.
+**
+** This method is for inspecting and debugging the property 
+** system.  Please use __system_property_find() instead.
+**
+** Order of results may change from call to call.  This is
+** not a bug.
+*/ 
+const prop_info *__system_property_find_nth(unsigned n);
+
+#endif