1 /* $NetBSD: mktemp.c,v 1.7 1997/04/08 06:14:39 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 39 #endif 40 static char rcsid[] = "$NetBSD: mktemp.c,v 1.7 1997/04/08 06:14:39 lukem Exp $"; 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/types.h> 44 #include <sys/stat.h> 45 #include <fcntl.h> 46 #include <errno.h> 47 #include <stdio.h> 48 #include <ctype.h> 49 #include <unistd.h> 50 51 static int _gettemp(); 52 53 int 54 mkstemp(path) 55 char *path; 56 { 57 int fd; 58 59 return (_gettemp(path, &fd) ? fd : -1); 60 } 61 62 char * 63 _mktemp(path) 64 char *path; 65 { 66 return (_gettemp(path, (int *)NULL) ? path : (char *)NULL); 67 } 68 69 __warn_references(mktemp, 70 "warning: mktemp() possibly used unsafely, consider using mkstemp()"); 71 72 char * 73 mktemp(path) 74 char *path; 75 { 76 return (_mktemp(path)); 77 } 78 79 static int 80 _gettemp(path, doopen) 81 char *path; 82 register int *doopen; 83 { 84 extern int errno; 85 register char *start, *trv; 86 struct stat sbuf; 87 u_int pid; 88 89 pid = getpid(); 90 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 91 while (*--trv == 'X') { 92 *trv = (pid % 10) + '0'; 93 pid /= 10; 94 } 95 96 /* 97 * check the target directory; if you have six X's and it 98 * doesn't exist this runs for a *very* long time. 99 */ 100 for (start = trv + 1;; --trv) { 101 if (trv <= path) 102 break; 103 if (*trv == '/') { 104 *trv = '\0'; 105 if (stat(path, &sbuf)) 106 return (0); 107 if (!S_ISDIR(sbuf.st_mode)) { 108 errno = ENOTDIR; 109 return (0); 110 } 111 *trv = '/'; 112 break; 113 } 114 } 115 116 for (;;) { 117 if (doopen) { 118 if ((*doopen = 119 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 120 return (1); 121 if (errno != EEXIST) 122 return (0); 123 } 124 else if (lstat(path, &sbuf)) 125 return (errno == ENOENT ? 1 : 0); 126 127 /* tricky little algorithm for backward compatibility */ 128 for (trv = start;;) { 129 if (!*trv) 130 return (0); 131 if (*trv == 'z') 132 *trv++ = 'a'; 133 else { 134 if (isdigit(*trv)) 135 *trv = 'a'; 136 else 137 ++*trv; 138 break; 139 } 140 } 141 } 142 /*NOTREACHED*/ 143 } 144