1 files changed, 8 insertions, 0 deletions
diff --git a/lib/libc/ctype/isalpha.c b/lib/libc/ctype/isalpha.c
new file mode 100644
index 00000000..d046c09e
--- /dev/null
+++ b/lib/libc/ctype/isalpha.c
@@ -0,0 +1,8 @@
+#include <libc.h>
+
+int isalpha(int c)
+{
+	return ((unsigned)c | 32) - 'a' < 26;
+}
+
+weak_reference(isalpha, isalpha_l);