Move C stdlib to lib/libk

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/libk/string/itoa.c b/lib/libk/string/itoa.c
new file mode 100644
index 0000000..2db9768
--- /dev/null
+++ b/lib/libk/string/itoa.c
@@ -0,0 +1,30 @@
+#include <stdbool.h>
+#include <string.h>
+
+static const char *numbers = "0123456789abcdef";
+
+char *
+utoa(char *p, unsigned x, int base)
+{
+  p += 3 * sizeof(unsigned);
+  *--p = '\0';
+
+  do {
+    *--p = numbers[x % base];
+    x /= base;
+  } while (x);
+
+  return p;
+}
+
+char *
+itoa(char *p, int x, int base)
+{
+  const bool is_negative = (x < 0);
+  if (is_negative) x = -x;
+
+  p = utoa(p, x, base);
+
+  if (is_negative) *--p = '-';
+  return p;
+}