1 files changed, 6 insertions, 0 deletions
diff --git a/user/lib/isdigit.c b/user/lib/isdigit.c
new file mode 100644
index 0000000..aa93ced
--- /dev/null
+++ b/user/lib/isdigit.c
@@ -0,0 +1,6 @@
+#include <ctype.h>
+
+int isdigit(int c)
+{
+	return c >= '0' && c <= '9';
+}