X-Git-Url: https://pd.if.org/git/?p=pdclib;a=blobdiff_plain;f=functions%2Fstdio%2Fungetc.c;h=560099d4e20737f213804051c5ada2c576b19fcc;hp=f15d8a3b8a66de75ab1bcff32a4085ddbcd0c945;hb=da0f3f353d417fed71f358a48d5d5394145e460d;hpb=0a5395faab237ba9008352b0f4bee9659bbd3d5f

diff --git a/functions/stdio/ungetc.c b/functions/stdio/ungetc.c
index f15d8a3..560099d 100644
--- a/functions/stdio/ungetc.c
+++ b/functions/stdio/ungetc.c
@@ -1,20 +1,67 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
+/* ungetc( int, FILE * )
 
-int ungetc( int c, FILE * stream ) { /* TODO */ };
+   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"
 
-/* PDPC code - unreviewed
+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