X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Fungetc.c;h=001735b533c04361648b2c3eb5475cdced99faac;hb=526e9954c39f30819e421cb74e82aa59d5a41013;hp=c355afcd0c7c4b9f7f5336f3ac5ad94a93a470db;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec;p=pdclib

diff --git a/functions/stdio/ungetc.c b/functions/stdio/ungetc.c
index c355afc..001735b 100644
--- a/functions/stdio/ungetc.c
+++ b/functions/stdio/ungetc.c
@@ -1,8 +1,33 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-int ungetc( int c, FILE * stream ) { /* TODO */ };
+/* $Id$ */
+
+/* ungetc( int, FILE * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <stdio.h>
+
+#ifndef REGTEST
+
+int ungetc( int c, struct _PDCLIB_file_t * stream )
+{
+    if ( c == EOF || stream->ungetidx == _PDCLIB_UNGETCBUFSIZE )
+    {
+        return -1;
+    }
+    return stream->ungetbuf[stream->ungetidx++] = (unsigned char) c;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    /* Testing covered by ftell.c */
+    return TEST_RESULTS;
+}
+
+#endif