X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Fungetc.c;h=59d2b57f6a00492e895eba080b261c45ac785f92;hb=b5b6c4a890795ea76f9b92b817b0a83c6bb4862c;hp=1bd7323ba80eb7345f26586de79d48912e386439;hpb=c8f799d852e3698468a78954d82588e841cc0b70;p=pdclib.old

diff --git a/functions/stdio/ungetc.c b/functions/stdio/ungetc.c
index 1bd7323..59d2b57 100644
--- a/functions/stdio/ungetc.c
+++ b/functions/stdio/ungetc.c
@@ -1,20 +1,69 @@
-/* ----------------------------------------------------------------------------
- * $Id$
- * ----------------------------------------------------------------------------
- * Public Domain C Library - http://pdclib.sourceforge.net
- * This code is Public Domain. Use, modify, and redistribute at will.
- * --------------------------------------------------------------------------*/
+/* $Id$ */
 
-int ungetc( int c, FILE * stream ) { /* TODO */ };
+/* ungetc( int, FILE * )
 
-/* PDPC code - unreviewed
+   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
+#include <_PDCLIB_io.h>
+
+int _PDCLIB_ungetc_unlocked( int c, FILE * stream )
 {
-    if ((stream->ungetCh != -1) || (c == EOF))
+    if ( c == EOF || stream->ungetidx == _PDCLIB_UNGETCBUFSIZE )
     {
-        return (EOF);
+        return -1;
     }
-    stream->ungetCh = (unsigned char)c;
-    stream->quickText = 0;
-    return ((unsigned char)c);
+    return stream->ungetbuf[stream->ungetidx++] = (unsigned char) c;
 }
-*/
+
+int ungetc( int c, FILE * stream )
+{
+    _PDCLIB_flockfile( stream );
+    int r = _PDCLIB_ungetc_unlocked( c, stream );
+    _PDCLIB_funlockfile( stream);
+    return r;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+#include <stdlib.h>
+
+const char* hellostr = "Hello, world!";
+
+int main( void )
+{
+    // Also see ftell() for some testing
+
+    // PDCLIB-18: fread ignores ungetc
+    size_t bufsz = strlen( hellostr ) + 1;
+    char * buf = malloc( bufsz );
+    FILE * fh;
+
+    // Also fgets
+    TESTCASE( ( fh = tmpfile() ) != NULL );
+    TESTCASE( fputs(hellostr, fh) == 0 );
+    rewind(fh);
+    TESTCASE( fgetc( fh ) == 'H' );
+    TESTCASE( ungetc( 'H', fh ) == 'H' );
+    TESTCASE( fgets( buf, bufsz, fh ) != NULL );
+    TESTCASE( strcmp( buf, hellostr ) == 0 );
+
+    // fread
+    rewind(fh);
+    TESTCASE( fgetc( fh ) == 'H' );
+    TESTCASE( ungetc( 'H', fh ) == 'H' );
+    TESTCASE( fread( buf, bufsz - 1, 1, fh ) == 1 );
+    TESTCASE( strncmp( buf, hellostr, bufsz - 1 ) == 0 );
+
+
+
+    return TEST_RESULTS;
+}
+
+#endif