1 files changed, 31 insertions, 0 deletions
diff --git a/src/user/lib/ctype.c b/src/user/lib/ctype.c
new file mode 100644
index 0000000..b702703
--- /dev/null
+++ b/src/user/lib/ctype.c
@@ -0,0 +1,31 @@
+#include <ctype.h>
+
+int isalpha(int c) {
+	return islower(c) || isupper(c);
+}
+
+int isalnum(int c) {
+	return isalpha(c) || isdigit(c);
+}
+
+int isdigit(int c) {
+	return '0' <= c && c <= '9';
+}
+
+int islower(int c) {
+	return 'a' <= c && c <= 'z';
+}
+
+int isspace(int c) {
+	return c == ' '
+		|| c == '\f'
+		|| c == '\n'
+		|| c == '\r'
+		|| c == '\t'
+		|| c == '\v';
+}
+
+int isupper(int c) {
+	return 'A' <= c && c <= 'Z';
+}
+