1 /* 2 * Copyright (c) 1987 Regents of the University of California. 3 * 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 5.10 (Berkeley) 2/24/91"; 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 44 static int _gettemp(); 45 46 mkstemp(path) 47 char *path; 48 { 49 int fd; 50 51 return (_gettemp(path, &fd) ? fd : -1); 52 } 53 54 char * 55 mktemp(path) 56 char *path; 57 { 58 return(_gettemp(path, (int *)NULL) ? path : (char *)NULL); 59 } 60 61 static 62 _gettemp(path, doopen) 63 char *path; 64 register int *doopen; 65 { 66 extern int errno; 67 register char *start, *trv; 68 struct stat sbuf; 69 u_int pid; 70 71 pid = getpid(); 72 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 73 while (*--trv == 'X') { 74 *trv = (pid % 10) + '0'; 75 pid /= 10; 76 } 77 78 /* 79 * check the target directory; if you have six X's and it 80 * doesn't exist this runs for a *very* long time. 81 */ 82 for (start = trv + 1;; --trv) { 83 if (trv <= path) 84 break; 85 if (*trv == '/') { 86 *trv = '\0'; 87 if (stat(path, &sbuf)) 88 return(0); 89 if (!S_ISDIR(sbuf.st_mode)) { 90 errno = ENOTDIR; 91 return(0); 92 } 93 *trv = '/'; 94 break; 95 } 96 } 97 98 for (;;) { 99 if (doopen) { 100 if ((*doopen = 101 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 102 return(1); 103 if (errno != EEXIST) 104 return(0); 105 } 106 else if (stat(path, &sbuf)) 107 return(errno == ENOENT ? 1 : 0); 108 109 /* tricky little algorithm for backward compatibility */ 110 for (trv = start;;) { 111 if (!*trv) 112 return(0); 113 if (*trv == 'z') 114 *trv++ = 'a'; 115 else { 116 if (isdigit(*trv)) 117 *trv = 'a'; 118 else 119 ++*trv; 120 break; 121 } 122 } 123 } 124 /*NOTREACHED*/ 125 } 126