1 files changed, 28 insertions, 0 deletions
diff --git a/src/user/lib/libc/std/ctype.c b/src/user/lib/libc/std/ctype.c
new file mode 100644
index 0000000..f0e7750
--- /dev/null
+++ b/src/user/lib/libc/std/ctype.c
@@ -0,0 +1,28 @@
+#include <ctype.h>
+
+
+int isalpha(int c) {
+	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
+}
+
+int isdigit(int c) {
+	return (c >= '0' && c <= '9');
+}
+
+int isalnum(int c) {
+	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9');
+}
+
+int tolower(int c) {
+	if (c >= 'A' && c <= 'Z') {
+		return c + ('a' - 'A');
+	}
+	return c;
+}
+
+int toupper(int c) {
+	if (c >= 'a' && c <= 'z') {
+		return c - ('a' - 'A');
+	}
+	return c;
+}