X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Fclearerr.c;h=20af80f298b4a1e792e6e8de80b5cce58f4e977a;hb=0e35e82c5e9a0804864839e8fc0e985b1ae41f07;hp=1adce827e840a6d67bbdb69ee7897bb87700338c;hpb=dcc8a8e99f69e090a03b7b868443addbc0817820;p=pdclib.old

diff --git a/functions/stdio/clearerr.c b/functions/stdio/clearerr.c
index 1adce82..20af80f 100644
--- a/functions/stdio/clearerr.c
+++ b/functions/stdio/clearerr.c
@@ -1,8 +1,61 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-void clearerr( FILE * stream ) { /* TODO */ };
+/* $Id$ */
+
+/* clearerr( 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
+#include <_PDCLIB_io.h>
+
+void clearerr_unlocked( FILE * stream )
+{
+    stream->status &= ~( _PDCLIB_ERRORFLAG | _PDCLIB_EOFFLAG );
+}
+
+void clearerr( FILE * stream )
+{
+    flockfile( stream );
+    clearerr_unlocked( stream );
+    funlockfile( stream );
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    FILE * fh;
+    TESTCASE( ( fh = tmpfile() ) != NULL );
+    /* Flags should be clear */
+    TESTCASE( ! ferror( fh ) );
+    TESTCASE( ! feof( fh ) );
+    /* Reading from input stream - should provoke error */
+    /* FIXME: Apparently glibc disagrees on this assumption. How to provoke error on glibc? */
+    TESTCASE( fgetc( fh ) == EOF );
+    TESTCASE( ferror( fh ) );
+    TESTCASE( ! feof( fh ) );
+    /* clearerr() should clear flags */
+    clearerr( fh );
+    TESTCASE( ! ferror( fh ) );
+    TESTCASE( ! feof( fh ) );
+    /* Reading from empty stream - should provoke EOF */
+    rewind( fh );
+    TESTCASE( fgetc( fh ) == EOF );
+    TESTCASE( ! ferror( fh ) );
+    TESTCASE( feof( fh ) );
+    /* clearerr() should clear flags */
+    clearerr( fh );
+    TESTCASE( ! ferror( fh ) );
+    TESTCASE( ! feof( fh ) );
+    TESTCASE( fclose( fh ) == 0 );
+    return TEST_RESULTS;
+}
+
+#endif
+