xref: /titanic_41/usr/src/cmd/sendmail/libsm/fpurge.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
3  *      All rights reserved.
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * By using this file, you agree to the terms and conditions set
11  * forth in the LICENSE file which can be found at the top level of
12  * the sendmail distribution.
13  */
14 
15 #pragma ident	"%Z%%M%	%I%	%E% SMI"
16 
17 #include <sm/gen.h>
18 SM_RCSID("@(#)$Id: fpurge.c,v 1.18 2001/01/28 00:29:35 ca Exp $")
19 #include <stdlib.h>
20 #include <errno.h>
21 #include <sm/io.h>
22 #include <sm/assert.h>
23 #include "local.h"
24 
25 /*
26 **  SM_IO_PURGE -- purge/empty the buffer without committing buffer content
27 **
28 **	Parameters:
29 **		fp -- file pointer to purge
30 **
31 **	Returns:
32 **		Failure: returns SM_IO_EOF and sets errno
33 **		Success: returns 0 (zero)
34 */
35 
36 int
37 sm_io_purge(fp)
38 	register SM_FILE_T *fp;
39 {
40 	SM_REQUIRE_ISA(fp, SmFileMagic);
41 	if (!fp->f_flags)
42 	{
43 		errno = EBADF;
44 		return SM_IO_EOF;
45 	}
46 
47 	if (HASUB(fp))
48 		FREEUB(fp);
49 	fp->f_p = fp->f_bf.smb_base;
50 	fp->f_r = 0;
51 
52 	/* implies SMFBF */
53 	fp->f_w = fp->f_flags & (SMLBF|SMNBF) ? 0 : fp->f_bf.smb_size;
54 	return 0;
55 }
56