1 /* $NetBSD: mktemp.c,v 1.5 1995/02/02 02:10:09 jtc 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 1.5 1995/02/02 02:10:09 jtc 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 static int 70 _gettemp(path, doopen) 71 char *path; 72 register int *doopen; 73 { 74 extern int errno; 75 register char *start, *trv; 76 struct stat sbuf; 77 u_int pid; 78 79 pid = getpid(); 80 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 81 while (*--trv == 'X') { 82 *trv = (pid % 10) + '0'; 83 pid /= 10; 84 } 85 86 /* 87 * check the target directory; if you have six X's and it 88 * doesn't exist this runs for a *very* long time. 89 */ 90 for (start = trv + 1;; --trv) { 91 if (trv <= path) 92 break; 93 if (*trv == '/') { 94 *trv = '\0'; 95 if (stat(path, &sbuf)) 96 return(0); 97 if (!S_ISDIR(sbuf.st_mode)) { 98 errno = ENOTDIR; 99 return(0); 100 } 101 *trv = '/'; 102 break; 103 } 104 } 105 106 for (;;) { 107 if (doopen) { 108 if ((*doopen = 109 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 110 return(1); 111 if (errno != EEXIST) 112 return(0); 113 } 114 else if (stat(path, &sbuf)) 115 return(errno == ENOENT ? 1 : 0); 116 117 /* tricky little algorithm for backward compatibility */ 118 for (trv = start;;) { 119 if (!*trv) 120 return(0); 121 if (*trv == 'z') 122 *trv++ = 'a'; 123 else { 124 if (isdigit(*trv)) 125 *trv = 'a'; 126 else 127 ++*trv; 128 break; 129 } 130 } 131 } 132 /*NOTREACHED*/ 133 } 134