From e85e3b53e8e4488ad90ad9c08e410d0b524fd16c Mon Sep 17 00:00:00 2001
From: Greg Haerr <greg@censoft.com>
Date: Sat, 16 Nov 2024 19:23:26 -0800
Subject: [PATCH] Add strupr and strlwr

---
 libc/include/string.h |  3 +++
 libc/string/Makefile  |  2 ++
 libc/string/strlwr.c  | 12 ++++++++++++
 libc/string/strupr.c  | 12 ++++++++++++
 4 files changed, 29 insertions(+)
 create mode 100644 libc/string/strlwr.c
 create mode 100644 libc/string/strupr.c

diff --git a/libc/include/string.h b/libc/include/string.h
index 7d4fa0557..ee7bb2621 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -51,6 +51,9 @@ char *strsep(char **, const char *);
 size_t strcspn(const char *, const char *);
 size_t strspn(const char *, const char *);
 
+char *strlwr(char *str);
+char *strupr(char *str);
+
 /* Linux silly hour */
 char *strfry(char *);
 
diff --git a/libc/string/Makefile b/libc/string/Makefile
index 28a653ee1..590701e2b 100644
--- a/libc/string/Makefile
+++ b/libc/string/Makefile
@@ -31,6 +31,8 @@ OBJS = \
 	strspn.o \
 	strstr.o \
 	strtok.o \
+	strlwr.o \
+	strupr.o \
 	# end of list
 
 .PHONY: all
diff --git a/libc/string/strlwr.c b/libc/string/strlwr.c
new file mode 100644
index 000000000..753991518
--- /dev/null
+++ b/libc/string/strlwr.c
@@ -0,0 +1,12 @@
+#include <string.h>
+#include <ctype.h>
+
+char *
+strlwr(char *str)
+{
+    unsigned char *p;
+
+    for (p = (unsigned char *)str; *p != '\0'; p++)
+        *p = tolower(*p);
+    return str;
+}
diff --git a/libc/string/strupr.c b/libc/string/strupr.c
new file mode 100644
index 000000000..1ecdbe539
--- /dev/null
+++ b/libc/string/strupr.c
@@ -0,0 +1,12 @@
+#include <string.h>
+#include <ctype.h>
+
+char *
+strupr(char *str)
+{
+    unsigned char *p;
+
+    for (p = (unsigned char *)str; *p != '\0'; p++)
+        *p = toupper(*p);
+    return str;
+}