init: Add support for ${x.y:-default} expansion
commit 00ede7d2626f9343d330dc6f5286bba3e99e41d0 (init: do
expand_props before calling the builtins) broke logpersist
Bug: 28120456
Bug: 22654233
Change-Id: Ib4d8231665b26ac083b02243177493fab41c8978
diff --git a/init/util.cpp b/init/util.cpp
index 750e040..69f6566 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -489,6 +489,7 @@
* - will accept $$ as a literal $.
* - no nested property expansion, i.e. ${foo.${bar}} is not supported,
* bad things will happen
+ * - ${x.y:-default} will return default value if property empty.
*/
while (*src_ptr) {
const char* c;
@@ -511,6 +512,7 @@
}
std::string prop_name;
+ std::string def_val;
if (*c == '{') {
c++;
const char* end = strchr(c, '}');
@@ -521,6 +523,11 @@
}
prop_name = std::string(c, end);
c = end + 1;
+ size_t def = prop_name.find(":-");
+ if (def < prop_name.size()) {
+ def_val = prop_name.substr(def + 2);
+ prop_name = prop_name.substr(0, def);
+ }
} else {
prop_name = c;
ERROR("using deprecated syntax for specifying property '%s', use ${name} instead\n",
@@ -535,9 +542,12 @@
std::string prop_val = property_get(prop_name.c_str());
if (prop_val.empty()) {
- ERROR("property '%s' doesn't exist while expanding '%s'\n",
- prop_name.c_str(), src.c_str());
- return false;
+ if (def_val.empty()) {
+ ERROR("property '%s' doesn't exist while expanding '%s'\n",
+ prop_name.c_str(), src.c_str());
+ return false;
+ }
+ prop_val = def_val;
}
dst->append(prop_val);
