1 files changed, 33 insertions, 1 deletions
diff --git a/lib/stdio.h b/lib/stdio.h
index 201cce1..4711a29 100644
--- a/lib/stdio.h
+++ b/lib/stdio.h
@@ -1,6 +1,38 @@
 #pragma once
 
+#include <stdarg.h>
+
+/** An object type used for streams */
+typedef struct FILE_t {
+  int id;
+  /** Functions that prints a character to the stream */
+  void (*putc)(const struct FILE_t *, char);
+  /** Function that prints a string to the stream */
+  int (*puts)(const struct FILE_t *, const char *, int);
+  /** Flush all buffers */
+  void (*flush)(const struct FILE_t *);
+} FILE;
+
+/** A FILE value corresponding to stdin, the keyboard buffer */
+extern FILE *stdin;
+/** A FILE value corresponding to stdout, the display */
+extern FILE *stdout;
+/** A FILE value corresponding to stderr, the uart */
+extern FILE *stderr;
+
 /**
- * Supports %s (string), %d (decimal), %u (unsigned), %x (hexadecimal)
+ * Write the formatted string to stdout
+ *
+ * Supports ``%s`` (string), ``%d`` (decimal), ``%u`` (unsigned), ``%x`` (hexadecimal)
  */
 int printf(const char *restrict format, ...);
+
+/**
+ * Write the formatted string to stream; see printf
+ */
+int fprintf(FILE *restrict stream, const char *restrict format, ...);
+
+/**
+ * Write the formatted string to stream; see printf
+ */
+int vfprintf(FILE *restrict stream, const char *restrict format, va_list ap);