From abafa63be192cedb745b7c54e5fa12d54f37de32 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx@kernel.org>
Date: Mon, 17 Feb 2025 12:26:41 +0100
Subject: [PATCH] lib/string/ctype/strtoascii/: strtolower(): Add API

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 lib/Makefile.am                          |  2 ++
 lib/string/ctype/strtoascii/strtolower.c | 10 +++++++
 lib/string/ctype/strtoascii/strtolower.h | 34 ++++++++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 lib/string/ctype/strtoascii/strtolower.c
 create mode 100644 lib/string/ctype/strtoascii/strtolower.h

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 0c0284a9b..279971bda 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -183,6 +183,8 @@ libshadow_la_SOURCES = \
 	sssd.h \
 	string/ctype/strisascii/strisdigit.c \
 	string/ctype/strisascii/strisdigit.h \
+	string/ctype/strtoascii/strtolower.c \
+	string/ctype/strtoascii/strtolower.h \
 	string/memset/memzero.c \
 	string/memset/memzero.h \
 	string/sprintf/snprintf.c \
diff --git a/lib/string/ctype/strtoascii/strtolower.c b/lib/string/ctype/strtoascii/strtolower.c
new file mode 100644
index 000000000..b46e19a81
--- /dev/null
+++ b/lib/string/ctype/strtoascii/strtolower.c
@@ -0,0 +1,10 @@
+// SPDX-FileCopyrightText: 2025, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "string/ctype/strtoascii/strtolower.h"
+
+
+extern inline char *strtolower(char *str);
diff --git a/lib/string/ctype/strtoascii/strtolower.h b/lib/string/ctype/strtoascii/strtolower.h
new file mode 100644
index 000000000..a19e851b0
--- /dev/null
+++ b/lib/string/ctype/strtoascii/strtolower.h
@@ -0,0 +1,34 @@
+// SPDX-FileCopyrightText: 2025, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_STRING_CTYPE_STRTOASCII_STRTOLOWER_H_
+#define SHADOW_INCLUDE_LIB_STRING_CTYPE_STRTOASCII_STRTOLOWER_H_
+
+
+#include <config.h>
+
+#include <ctype.h>
+
+#include "string/strcmp/streq.h"
+
+
+inline char *strtolower(char *str);
+
+
+// string convert-to lower-case
+// Like tolower(3), but convert all characters in the string.
+// Returns the input pointer.
+inline char *
+strtolower(char *str)
+{
+	for (char *s = str; !streq(s, ""); s++) {
+		unsigned char  c = *s;
+
+		*s = tolower(c);
+	}
+	return str;
+}
+
+
+#endif  // include guard
-- 
2.47.3