X-Git-Url: https://pd.if.org/git/?p=pdclib;a=blobdiff_plain;f=functions%2Fstdio%2Fftell.c;h=9731e33368ae23364110f22dba1421ddd1d5cc0c;hp=9518033f384901c3835778becbebbc185c51ad59;hb=da0f3f353d417fed71f358a48d5d5394145e460d;hpb=1d9d92ba957a0b8307c9a65c35867fde68e6533b

diff --git a/functions/stdio/ftell.c b/functions/stdio/ftell.c
index 9518033..9731e33 100644
--- a/functions/stdio/ftell.c
+++ b/functions/stdio/ftell.c
@@ -1,14 +1,96 @@
-/* ----------------------------------------------------------------------------
- * $Id$
- * ----------------------------------------------------------------------------
- * Public Domain C Library - http://pdclib.sourceforge.net
- * This code is Public Domain. Use, modify, and redistribute at will.
- * --------------------------------------------------------------------------*/
+/* ftell( FILE * )
 
-long ftell( 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>
+#include <stdint.h>
+#include <limits.h>
+#include <errno.h>
+
+#ifndef REGTEST
+#include "_PDCLIB_io.h"
+
+long int _PDCLIB_ftell_unlocked( FILE * stream )
+{
+    uint_fast64_t off64 = _PDCLIB_ftell64_unlocked( stream );
+
+    if ( off64 > LONG_MAX )
+    {
+        /* integer overflow */
+        errno = ERANGE;
+        return -1;
+    }
+    return off64;
+}
 
-/* PDPC code - unreviewed
+long int ftell( FILE * stream )
 {
-    return (stream->bufStartR + (stream->upto - stream->fbuf));
+    _PDCLIB_flockfile( stream );
+    long int off = _PDCLIB_ftell_unlocked( stream );
+    _PDCLIB_funlockfile( stream );
+    return off;
 }
-*/
+
+#endif
+
+#ifdef TEST
+#include "_PDCLIB_test.h"
+#include <stdlib.h>
+#ifndef REGTEST
+#include "_PDCLIB_io.h"
+#endif
+
+int main( void )
+{
+    /* Testing all the basic I/O functions individually would result in lots
+       of duplicated code, so I took the liberty of lumping it all together
+       here.
+    */
+    /* The following functions delegate their tests to here:
+       fgetc fflush rewind fputc ungetc fseek
+       flushbuffer seek fillbuffer prepread prepwrite
+    */
+    char * buffer = (char*)malloc( 4 );
+    FILE * fh;
+    TESTCASE( ( fh = tmpfile() ) != NULL );
+    TESTCASE( setvbuf( fh, buffer, _IOLBF, 4 ) == 0 );
+    /* Testing ungetc() at offset 0 */
+    rewind( fh );
+    TESTCASE( ungetc( 'x', fh ) == 'x' );
+    TESTCASE( ftell( fh ) == -1l );
+    rewind( fh );
+    TESTCASE( ftell( fh ) == 0l );
+    /* Commence "normal" tests */
+    TESTCASE( fputc( '1', fh ) == '1' );
+    TESTCASE( fputc( '2', fh ) == '2' );
+    TESTCASE( fputc( '3', fh ) == '3' );
+    /* Positions incrementing as expected? */
+    TESTCASE( ftell( fh ) == 3l );
+    TESTCASE_NOREG( fh->pos.offset == 0l );
+    TESTCASE_NOREG( fh->bufidx == 3l );
+    /* Buffer properly flushed when full? */
+    TESTCASE( fputc( '4', fh ) == '4' );
+    TESTCASE_NOREG( fh->pos.offset == 4l );
+    TESTCASE_NOREG( fh->bufidx == 0 );
+    /* fflush() resetting positions as expected? */
+    TESTCASE( fputc( '5', fh ) == '5' );
+    TESTCASE( fflush( fh ) == 0 );
+    TESTCASE( ftell( fh ) == 5l );
+    TESTCASE_NOREG( fh->pos.offset == 5l );
+    TESTCASE_NOREG( fh->bufidx == 0l );
+    /* rewind() resetting positions as expected? */
+    rewind( fh );
+    TESTCASE( ftell( fh ) == 0l );
+    TESTCASE_NOREG( fh->pos.offset == 0 );
+    TESTCASE_NOREG( fh->bufidx == 0 );
+    /* Reading back first character after rewind for basic read check */
+    TESTCASE( fgetc( fh ) == '1' );
+    /* TODO: t.b.c. */
+    TESTCASE( fclose( fh ) == 0 );
+    return TEST_RESULTS;
+}
+
+#endif
+