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 #if 0 36 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 37 #endif 38 static const char rcsid[] = 39 "$Id$"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 #include <sys/stat.h> 44 #include <fcntl.h> 45 #include <errno.h> 46 #include <stdio.h> 47 #include <ctype.h> 48 #include <unistd.h> 49 50 static int _gettemp(char *, int *); 51 52 int 53 mkstemp(path) 54 char *path; 55 { 56 int fd; 57 58 return (_gettemp(path, &fd) ? fd : -1); 59 } 60 61 char * 62 mktemp(path) 63 char *path; 64 { 65 return(_gettemp(path, (int *)NULL) ? path : (char *)NULL); 66 } 67 68 static int 69 _gettemp(path, doopen) 70 char *path; 71 register int *doopen; 72 { 73 register char *start, *trv; 74 struct stat sbuf; 75 pid_t pid; 76 77 pid = getpid(); 78 for (trv = path; *trv; ++trv); /* extra X's get set to 0's */ 79 while (*--trv == 'X') { 80 *trv = (pid % 10) + '0'; 81 pid /= 10; 82 } 83 84 /* 85 * check the target directory; if you have six X's and it 86 * doesn't exist this runs for a *very* long time. 87 */ 88 for (start = trv + 1;; --trv) { 89 if (trv <= path) 90 break; 91 if (*trv == '/') { 92 *trv = '\0'; 93 if (stat(path, &sbuf)) 94 return(0); 95 if (!S_ISDIR(sbuf.st_mode)) { 96 errno = ENOTDIR; 97 return(0); 98 } 99 *trv = '/'; 100 break; 101 } 102 } 103 104 for (;;) { 105 if (doopen) { 106 if ((*doopen = 107 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 108 return(1); 109 if (errno != EEXIST) 110 return(0); 111 } 112 else if (stat(path, &sbuf)) 113 return(errno == ENOENT ? 1 : 0); 114 115 /* tricky little algorithm for backward compatibility */ 116 for (trv = start;;) { 117 if (!*trv) 118 return(0); 119 if (*trv == 'z') 120 *trv++ = 'a'; 121 else { 122 if (isdigit(*trv)) 123 *trv = 'a'; 124 else 125 ++*trv; 126 break; 127 } 128 } 129 } 130 /*NOTREACHED*/ 131 } 132