1 files changed, 37 insertions, 0 deletions
diff --git a/src/stdio/ungetc.c b/src/stdio/ungetc.c
new file mode 100644
index 00000000..1c32ac1f
--- /dev/null
+++ b/src/stdio/ungetc.c
@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include "nonstd/io.h"
+
+/** push a character back into an input stream **/
+int ungetc(int c, FILE *stream)
+{
+	(void)c; (void)stream;
+	/* TODO */
+	/*
+	RETURN_SUCCESS(ARGUMENT(c));
+	RETURN_FAILURE(CONSTANT(EOF));
+	*/
+	return EOF;
+}
+
+/***
+pushes the characer ARGUMENT(c) (converted to an
+type(unsigned char)) into the input stream ARGUMENT(stream). Future function calls
+that read input will return the pushed character. Calls to seeking functions
+(e.g. FUNCTION(fseek), FUNCTION(fsetpos), or FUNCTION(rewind)) will discard pushed characters.
+The file associated with ARGUMENT(stream) is unchanged.
+
+At least one character can be pushed back. Multiple calls to THIS() without
+intervening read operations may fail.
+
+If macro(EOF) is specified for ARGUMENT(c), THIS() fails and the input stream
+is unchagned.
+
+A successfull call clears the end-of-file indicator for ARGUMENT(stream). The file
+position indicator is decremented.
+
+Calling THIS() on a binary stream when the file position indicator is zero
+is obsolete in ISO/IEC 9899:1999.
+***/
+/*
+STDC(1)
+*/