1 files changed, 9 insertions, 0 deletions
diff --git a/libc/ctype/_toupper.c b/libc/ctype/_toupper.c
new file mode 100644
index 0000000..db4e00d
--- /dev/null
+++ b/libc/ctype/_toupper.c
@@ -0,0 +1,9 @@
+#include <_ansi.h>
+#include <ctype.h>
+
+#undef _toupper
+int
+_DEFUN(_toupper,(c),int c)
+{
+  return islower(c) ? c - 'a' + 'A' : c;
+}