xref: /minix3/lib/libc/stdio/mktemp.c (revision 9a21d1a2fdca366d7697d6ecbfe4ed6d5851f9c7)
1 /*
2  * Copyright (c) 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <fcntl.h>
41 #include <errno.h>
42 #include <stdio.h>
43 #include <ctype.h>
44 #include <unistd.h>
45 #include <stdlib.h>
46 
47 static int _gettemp(char*,int*,int);
48 
49 int
50 mkstemp(path)
51 	char *path;
52 {
53 	int fd;
54 
55 	return (_gettemp(path, &fd, 0) ? fd : -1);
56 }
57 
58 char *
59 mktemp(path)
60 	char *path;
61 {
62 	return(_gettemp(path, (int *)NULL, 0) ? path : (char *)NULL);
63 }
64 
65 char *
66 mkdtemp(path)
67 	char *path;
68 {
69 	return(_gettemp(path, (int *)NULL, 1) ? path : (char *)NULL);
70 }
71 
72 static int
73 _gettemp(path, doopen, domkdir)
74 	char *path;
75 	register int *doopen;
76 	int domkdir;
77 {
78 	extern int errno;
79 	register char *start, *trv;
80 	struct stat sbuf;
81 	u_int pid;
82 	static int lastnames = 0;
83 	int names = 0;
84 
85 	pid = getpid();
86 	for (trv = path; *trv; ++trv);		/* extra X's get set to 0's */
87 	while (*--trv == 'X') {
88 		*trv = (pid % 10) + '0';
89 		pid /= 10;
90 	}
91 
92 	/*
93 	 * check the target directory; if you have six X's and it
94 	 * doesn't exist this runs for a *very* long time.
95 	 */
96 	for (start = trv + 1;; --trv) {
97 		if (trv <= path)
98 			break;
99 		if (*trv == '/') {
100 			*trv = '\0';
101 			if (stat(path, &sbuf))
102 				return(0);
103 			if (!S_ISDIR(sbuf.st_mode)) {
104 				errno = ENOTDIR;
105 				return(0);
106 			}
107 			*trv = '/';
108 			break;
109 		}
110 	}
111 
112 	for (;;) {
113 		/* tricky little algorithm for backward compatibility */
114 		for (trv = start;;) {
115 			if (!*trv)
116 				return(0);
117 			if (*trv == 'z')
118 				*trv++ = 'a';
119 			else {
120 				if (isdigit(*trv))
121 					*trv = 'a';
122 				else
123 					++*trv;
124 				break;
125 			}
126 		}
127 
128 		names++;
129 
130 		if(names <= lastnames)
131 			continue;
132 
133 		lastnames = names;
134 
135 		if (doopen) {
136 			if ((*doopen =
137 			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) {
138 				return(1);
139 			    }
140 			if (errno != EEXIST) {
141 				return(0);
142 			}
143 		} else if(domkdir) {
144 			if (mkdir(path, 0700) >= 0)
145 				return (1);
146 			if (errno != EEXIST)
147 				return (0);
148 		} else if (stat(path, &sbuf)) {
149 			return(errno == ENOENT ? 1 : 0);
150 		}
151 
152 	}
153 	/*NOTREACHED*/
154 }
155 
156 /*
157  * $PchId: mktemp.c,v 1.3 1995/11/20 19:10:39 philip Exp $
158  */
159