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 <unistd.h> 44 #include <ctype.h> 45 46 static int _gettemp(); 47 48 mkstemp(path) 49 char *path; 50 { 51 int fd; 52 53 return (_gettemp(path, &fd) ? fd : -1); 54 } 55 56 char * 57 mktemp(path) 58 char *path; 59 { 60 return(_gettemp(path, (int *)NULL) ? path : (char *)NULL); 61 } 62 63 static 64 _gettemp(path, doopen) 65 char *path; 66 register int *doopen; 67 { 68 extern int errno; 69 register char *start, *trv; 70 struct stat sbuf; 71 u_int pid; 72 73 pid = getpid(); 74 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 75 while (*--trv == 'X') { 76 *trv = (pid % 10) + '0'; 77 pid /= 10; 78 } 79 80 /* 81 * check the target directory; if you have six X's and it 82 * doesn't exist this runs for a *very* long time. 83 */ 84 for (start = trv + 1;; --trv) { 85 if (trv <= path) 86 break; 87 if (*trv == '/') { 88 *trv = '\0'; 89 if (stat(path, &sbuf)) 90 return(0); 91 if (!S_ISDIR(sbuf.st_mode)) { 92 errno = ENOTDIR; 93 return(0); 94 } 95 *trv = '/'; 96 break; 97 } 98 } 99 100 for (;;) { 101 if (doopen) { 102 if ((*doopen = 103 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 104 return(1); 105 if (errno != EEXIST) 106 return(0); 107 } 108 else if (stat(path, &sbuf)) 109 return(errno == ENOENT ? 1 : 0); 110 111 /* tricky little algorithm for backward compatibility */ 112 for (trv = start;;) { 113 if (!*trv) 114 return(0); 115 if (*trv == 'z') 116 *trv++ = 'a'; 117 else { 118 if (isdigit(*trv)) 119 *trv = 'a'; 120 else 121 ++*trv; 122 break; 123 } 124 } 125 } 126 /*NOTREACHED*/ 127 } 128