xref: /onnv-gate/usr/src/lib/libc/port/stdio/tmpfile.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
30*0Sstevel@tonic-gate /*	  All Rights Reserved  	*/
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate /*
34*0Sstevel@tonic-gate  *	tmpfile - return a pointer to an update file that can be
35*0Sstevel@tonic-gate  *		used for scratch. The file will automatically
36*0Sstevel@tonic-gate  *		go away if the program using it terminates.
37*0Sstevel@tonic-gate  */
38*0Sstevel@tonic-gate 
39*0Sstevel@tonic-gate #include "synonyms.h"
40*0Sstevel@tonic-gate #include "mtlib.h"
41*0Sstevel@tonic-gate #include <sys/types.h>
42*0Sstevel@tonic-gate #include <unistd.h>
43*0Sstevel@tonic-gate #include <stdio.h>
44*0Sstevel@tonic-gate #include <string.h>
45*0Sstevel@tonic-gate #include <stdlib.h>
46*0Sstevel@tonic-gate #include <thread.h>
47*0Sstevel@tonic-gate #include <synch.h>
48*0Sstevel@tonic-gate #include <sys/stat.h>
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate static char seed[] = { 'a', 'a', 'a', '\0' };
51*0Sstevel@tonic-gate static mutex_t seed_lk = DEFAULTMUTEX;
52*0Sstevel@tonic-gate 
53*0Sstevel@tonic-gate #define	XS "\bXXXXXX"		/* a '\b' character is prepended to this */
54*0Sstevel@tonic-gate 				/* string to avoid conflicts with names */
55*0Sstevel@tonic-gate 				/* generated by tmpnam() */
56*0Sstevel@tonic-gate /*ARGSUSED*/
57*0Sstevel@tonic-gate static FILE *
58*0Sstevel@tonic-gate _common(boolean_t large_file)
59*0Sstevel@tonic-gate {
60*0Sstevel@tonic-gate 	char	tfname[L_tmpnam];
61*0Sstevel@tonic-gate 	FILE	*p;
62*0Sstevel@tonic-gate 	char	*q;
63*0Sstevel@tonic-gate 	int	mkret;
64*0Sstevel@tonic-gate 	mode_t	current_umask;
65*0Sstevel@tonic-gate 
66*0Sstevel@tonic-gate 	(void) strcpy(tfname, P_tmpdir);
67*0Sstevel@tonic-gate 	lmutex_lock(&seed_lk);
68*0Sstevel@tonic-gate 	(void) strcat(tfname, seed);
69*0Sstevel@tonic-gate 	(void) strcat(tfname, XS);
70*0Sstevel@tonic-gate 
71*0Sstevel@tonic-gate 	q = seed;
72*0Sstevel@tonic-gate 	while (*q == 'z')
73*0Sstevel@tonic-gate 		*q++ = 'a';
74*0Sstevel@tonic-gate 	if (*q != '\0')
75*0Sstevel@tonic-gate 		++*q;
76*0Sstevel@tonic-gate 	lmutex_unlock(&seed_lk);
77*0Sstevel@tonic-gate 
78*0Sstevel@tonic-gate #if !defined(_LP64)
79*0Sstevel@tonic-gate 	if (large_file == B_TRUE) {
80*0Sstevel@tonic-gate 		if ((mkret = mkstemp64(tfname)) == -1)
81*0Sstevel@tonic-gate 			return (NULL);
82*0Sstevel@tonic-gate 	} else
83*0Sstevel@tonic-gate #endif
84*0Sstevel@tonic-gate 		if ((mkret = mkstemp(tfname)) == -1)
85*0Sstevel@tonic-gate 			return (NULL);
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate 	(void) unlink(tfname);
88*0Sstevel@tonic-gate 	current_umask = umask(0777);
89*0Sstevel@tonic-gate 	(void) umask(current_umask);
90*0Sstevel@tonic-gate 	(void) fchmod(mkret, 0666 & ~current_umask);
91*0Sstevel@tonic-gate 	if ((p = fdopen(mkret, "w+")) == NULL) {
92*0Sstevel@tonic-gate 		(void) close(mkret);
93*0Sstevel@tonic-gate 		return (NULL);
94*0Sstevel@tonic-gate 	}
95*0Sstevel@tonic-gate 
96*0Sstevel@tonic-gate 	return (p);
97*0Sstevel@tonic-gate }
98*0Sstevel@tonic-gate 
99*0Sstevel@tonic-gate #if !defined(_LP64)
100*0Sstevel@tonic-gate FILE *
101*0Sstevel@tonic-gate tmpfile64(void)
102*0Sstevel@tonic-gate {
103*0Sstevel@tonic-gate 	return (_common(B_TRUE));
104*0Sstevel@tonic-gate }
105*0Sstevel@tonic-gate #endif	/* _LP64 */
106*0Sstevel@tonic-gate 
107*0Sstevel@tonic-gate /*
108*0Sstevel@tonic-gate  * This is a bit confusing -- some explanation is in order.
109*0Sstevel@tonic-gate  *
110*0Sstevel@tonic-gate  * When we're compiled 64-bit, there's no point in distinguishing
111*0Sstevel@tonic-gate  * a "large" file from a "small" file -- they're all "large".
112*0Sstevel@tonic-gate  * The argument we pass to '_common' is ignored -- we always call
113*0Sstevel@tonic-gate  * mkstemp which will just do the right thing for us.
114*0Sstevel@tonic-gate  */
115*0Sstevel@tonic-gate FILE *
116*0Sstevel@tonic-gate tmpfile(void)
117*0Sstevel@tonic-gate {
118*0Sstevel@tonic-gate 	return (_common(B_FALSE));
119*0Sstevel@tonic-gate }
120