1 /* $NetBSD: gettemp.c,v 1.2 1998/07/27 16:05:07 mycroft 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 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: gettemp.c,v 1.2 1998/07/27 16:05:07 mycroft Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/types.h> 46 #include <sys/stat.h> 47 #include <fcntl.h> 48 #include <errno.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <ctype.h> 52 #include <unistd.h> 53 #include <errno.h> 54 #include "local.h" 55 56 int 57 __gettemp(path, doopen, domkdir) 58 char *path; 59 int *doopen; 60 int domkdir; 61 { 62 char *start, *trv; 63 struct stat sbuf; 64 u_int pid; 65 66 /* To guarantee multiple calls generate unique names even if 67 the file is not created. 676 different possibilities with 7 68 or more X's, 26 with 6 or less. */ 69 static char xtra[2] = "aa"; 70 int xcnt = 0; 71 72 pid = getpid(); 73 74 /* Move to end of path and count trailing X's. */ 75 for (trv = path; *trv; ++trv) 76 if (*trv == 'X') 77 xcnt++; 78 else 79 xcnt = 0; 80 81 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 82 if (*(trv-1) == 'X') 83 *--trv = xtra[0]; 84 if (xcnt > 6 && *(trv-1) == 'X') 85 *--trv = xtra[1]; 86 87 /* Set remaining X's to pid digits with 0's to the left. */ 88 while (*--trv == 'X') { 89 *trv = (pid % 10) + '0'; 90 pid /= 10; 91 } 92 93 /* update xtra for next call. */ 94 if (xtra[0] != 'z') 95 xtra[0]++; 96 else { 97 xtra[0] = 'a'; 98 if (xtra[1] != 'z') 99 xtra[1]++; 100 else 101 xtra[1] = 'a'; 102 } 103 104 /* 105 * check the target directory; if you have six X's and it 106 * doesn't exist this runs for a *very* long time. 107 */ 108 for (start = trv + 1;; --trv) { 109 if (trv <= path) 110 break; 111 if (*trv == '/') { 112 *trv = '\0'; 113 if (stat(path, &sbuf)) 114 return (0); 115 if (!S_ISDIR(sbuf.st_mode)) { 116 errno = ENOTDIR; 117 return (0); 118 } 119 *trv = '/'; 120 break; 121 } 122 } 123 124 for (;;) { 125 if (doopen) { 126 if ((*doopen = 127 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 128 return (1); 129 if (errno != EEXIST) 130 return (0); 131 } else if (domkdir) { 132 if (mkdir(path, 0700) >= 0) 133 return (1); 134 if (errno != EEXIST) 135 return (0); 136 } else if (lstat(path, &sbuf)) 137 return (errno == ENOENT ? 1 : 0); 138 139 /* tricky little algorithm for backward compatibility */ 140 for (trv = start;;) { 141 if (!*trv) 142 return (0); 143 if (*trv == 'z') 144 *trv++ = 'a'; 145 else { 146 if (isdigit(*trv)) 147 *trv = 'a'; 148 else 149 ++*trv; 150 break; 151 } 152 } 153 } 154 /*NOTREACHED*/ 155 } 156