freebsd-skq/lib/libc/stdio/flags.c
Jilles Tjoelker ef70de180c libc/stdio: Allow fopen/freopen modes in any order (except initial r/w/a).
Austin Group issue #411 requires 'e' to be accepted before and after 'x',
and encourages accepting the characters in any order, except the initial
'r', 'w' or 'a'.

Given that glibc accepts the characters after r/w/a in any order and that
diagnosing this problem may be hard, change our libc to behave that way as
well.
2013-09-06 13:47:16 +00:00

114 lines
3.0 KiB
C

/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/file.h>
#include <stdio.h>
#include <errno.h>
#include "local.h"
/*
* Return the (stdio) flags for a given mode. Store the flags
* to be passed to an _open() syscall through *optr.
* Return 0 on error.
*/
int
__sflags(const char *mode, int *optr)
{
int ret, m, o, known;
switch (*mode++) {
case 'r': /* open for reading */
ret = __SRD;
m = O_RDONLY;
o = 0;
break;
case 'w': /* open for writing */
ret = __SWR;
m = O_WRONLY;
o = O_CREAT | O_TRUNC;
break;
case 'a': /* open for appending */
ret = __SWR;
m = O_WRONLY;
o = O_CREAT | O_APPEND;
break;
default: /* illegal mode */
errno = EINVAL;
return (0);
}
do {
known = 1;
switch (*mode++) {
case 'b':
/* 'b' (binary) is ignored */
break;
case '+':
/* [rwa][b]\+ means read and write */
ret = __SRW;
m = O_RDWR;
break;
case 'x':
/* 'x' means exclusive (fail if the file exists) */
o |= O_EXCL;
break;
case 'e':
/* set close-on-exec */
o |= O_CLOEXEC;
break;
default:
known = 0;
break;
}
} while (known);
if ((o & O_EXCL) != 0 && m == O_RDONLY) {
errno = EINVAL;
return (0);
}
*optr = m | o;
return (ret);
}