From 2c4d5dc41505d28cff369cfbe8b17ac81106d936 Mon Sep 17 00:00:00 2001 From: Mike Lockwood Date: Tue, 7 Jun 2011 17:30:11 -0700 Subject: [PATCH] init: Add support for writing system property value to a file in init.rc The write command will write a property value if the value starts with a "$' For example: write /sys/class/android_usb/iSerial $ro.serialno Use double leading '$' if you need to write a string that starts with '$': write /data/foo $$hello to write "$hello" to /data/foo Change-Id: I55431ac7715a5347bb95c3a15aee97c575444dde --- init/builtins.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/init/builtins.c b/init/builtins.c index 23ef2245f..dad754541 100644 --- a/init/builtins.c +++ b/init/builtins.c @@ -527,7 +527,23 @@ int do_sysclktz(int nargs, char **args) int do_write(int nargs, char **args) { - return write_file(args[1], args[2]); + char *path = args[1]; + char *value = args[2]; + if (value[0] == '$') { + /* Write the value of a system property if value starts with '$' */ + value++; + if (value[0] != '$') { + value = property_get(value); + if (!value) { + ERROR("property %s has no value for writing to %s\n", value, path); + return -EINVAL; + } + } /* else fall through to support double '$' prefix for writing + * string literals that start with '$' + */ + } + + return write_file(path, value); } int do_copy(int nargs, char **args)