1 files changed, 14 insertions, 0 deletions
diff --git a/user/lib/ctoi.c b/user/lib/ctoi.c
new file mode 100644
index 0000000..efe4fec
--- /dev/null
+++ b/user/lib/ctoi.c
@@ -0,0 +1,14 @@
+#include <stdlib.h>
+
+int ctoi(char c)
+{
+	if (c >= '0' && c <= '9') {
+		return c - '0';
+	} else if (c >= 'A' && c <= 'Z') {
+		return c - 'A' + 10;
+	} else if (c >= 'a' && c <= 'z') {
+		return c - 'a' + 10;
+	} else {
+		return -1;
+	}
+}