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 45 static int _gettemp(); 46 47 mkstemp(path) 48 char *path; 49 { 50 int fd; 51 52 return (_gettemp(path, &fd) ? fd : -1); 53 } 54 55 char * 56 mktemp(path) 57 char *path; 58 { 59 return(_gettemp(path, (int *)NULL) ? path : (char *)NULL); 60 } 61 62 static 63 _gettemp(path, doopen) 64 char *path; 65 register int *doopen; 66 { 67 extern int errno; 68 register char *start, *trv; 69 struct stat sbuf; 70 u_int pid; 71 72 pid = getpid(); 73 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 74 while (*--trv == 'X') { 75 *trv = (pid % 10) + '0'; 76 pid /= 10; 77 } 78 79 /* 80 * check the target directory; if you have six X's and it 81 * doesn't exist this runs for a *very* long time. 82 */ 83 for (start = trv + 1;; --trv) { 84 if (trv <= path) 85 break; 86 if (*trv == '/') { 87 *trv = '\0'; 88 if (stat(path, &sbuf)) 89 return(0); 90 if (!S_ISDIR(sbuf.st_mode)) { 91 errno = ENOTDIR; 92 return(0); 93 } 94 *trv = '/'; 95 break; 96 } 97 } 98 99 for (;;) { 100 if (doopen) { 101 if ((*doopen = 102 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 103 return(1); 104 if (errno != EEXIST) 105 return(0); 106 } 107 else if (stat(path, &sbuf)) 108 return(errno == ENOENT ? 1 : 0); 109 110 /* tricky little algorithm for backward compatibility */ 111 for (trv = start;;) { 112 if (!*trv) 113 return(0); 114 if (*trv == 'z') 115 *trv++ = 'a'; 116 else { 117 if (isdigit(*trv)) 118 *trv = 'a'; 119 else 120 ++*trv; 121 break; 122 } 123 } 124 } 125 /*NOTREACHED*/ 126 } 127