1 files changed, 54 insertions, 0 deletions
diff --git a/lib/stdio/vfprintf.c b/lib/stdio/vfprintf.c
new file mode 100644
index 0000000..d24e43e
--- /dev/null
+++ b/lib/stdio/vfprintf.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <string.h>
+
+static char buffer[3 * sizeof(int) + 2];
+
+int
+vfprintf(FILE *restrict stream, const char *restrict format, va_list params)
+{
+  int written = 0;
+
+  int s = 0;
+  int l = 0;
+  for (int i = 0; format[i] != '\0'; ++i) {
+    if (format[i] == '%') {
+      written += stream->puts(stream, &format[s], l);
+      s = i + 2;
+      ++i;
+
+      switch (format[i]) {
+      case 's': {
+        const char *arg = va_arg(params, const char *);
+        written += stream->puts(stream, arg, -1);
+      } break;
+      case 'c': {
+        const int arg = va_arg(params, int);
+        stream->putc(stream, arg);
+        ++written;
+      } break;
+      case 'd': {
+        const char *arg = itoa(buffer, va_arg(params, int), 10);
+        written += stream->puts(stream, arg, -1);
+      } break;
+      case 'u': {
+        const char *arg = utoa(buffer, va_arg(params, unsigned int), 10);
+        written += stream->puts(stream, arg, -1);
+      } break;
+      case 'x': {
+        const char *arg = utoa(buffer, va_arg(params, unsigned int), 16);
+        written += stream->puts(stream, arg, -1);
+      } break;
+      }
+
+      l = 0;
+    }
+
+    else
+      ++l;
+  }
+
+  if (l > 0) { written += stream->puts(stream, &format[s], l); }
+
+  stream->flush(stream);
+  return written;
+}