1 files changed, 46 insertions, 0 deletions
diff --git a/src/locale/__setlocalecat.c b/src/locale/__setlocalecat.c
new file mode 100644
index 00000000..f1e4bf07
--- /dev/null
+++ b/src/locale/__setlocalecat.c
@@ -0,0 +1,46 @@
+#include <locale.h>
+#include <string.h>
+#include "locale_impl.h"
+#include "libc.h"
+#include "atomic.h"
+
+static const char envvars[][12] = {
+	"LC_CTYPE",
+	"LC_NUMERIC",
+	"LC_TIME",
+	"LC_COLLATE",
+	"LC_MONETARY",
+	"LC_MESSAGES",
+};
+
+int __setlocalecat(locale_t loc, int cat, const char *val)
+{
+	if (!*val) {
+		(val = getenv("LC_ALL")) ||
+		(val = getenv(envvars[cat])) ||
+		(val = getenv("LANG")) ||
+		(val = "C.UTF-8");
+	}
+
+	size_t n = strnlen(val, LOCALE_NAME_MAX);
+	int builtin = (val[0]=='C' && !val[1])
+		|| !strcmp(val, "C.UTF-8")
+		|| !strcmp(val, "POSIX");
+
+	switch (cat) {
+	case LC_CTYPE:
+		a_store(&loc->ctype_utf8, !builtin || val[1]=='.');
+		break;
+	case LC_MESSAGES:
+		if (builtin) {
+			loc->messages_name[0] = 0;
+		} else {
+			memcpy(loc->messages_name, val, n);
+			loc->messages_name[n] = 0;
+		}
+		/* fall through */
+	default:
+		break;
+	}
+	return 0;
+}