1 /* $NetBSD: gettemp.c,v 1.8 2002/09/14 04:27:21 thorpej 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 #if HAVE_CONFIG_H 37 #include "config.h" 38 #endif 39 40 #if !HAVE_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP 41 42 #include <sys/cdefs.h> 43 #if defined(LIBC_SCCS) && !defined(lint) 44 #if 0 45 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 46 #else 47 __RCSID("$NetBSD: gettemp.c,v 1.8 2002/09/14 04:27:21 thorpej Exp $"); 48 #endif 49 #endif /* LIBC_SCCS and not lint */ 50 51 #include <sys/types.h> 52 #include <sys/stat.h> 53 54 #include <assert.h> 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <unistd.h> 61 62 #if HAVE_CONFIG_H 63 #define GETTEMP gettemp 64 #else 65 #include "local.h" 66 #define GETTEMP __gettemp 67 #endif 68 69 int 70 GETTEMP(path, doopen, domkdir) 71 char *path; 72 int *doopen; 73 int domkdir; 74 { 75 char *start, *trv; 76 struct stat sbuf; 77 u_int pid; 78 79 /* To guarantee multiple calls generate unique names even if 80 the file is not created. 676 different possibilities with 7 81 or more X's, 26 with 6 or less. */ 82 static char xtra[2] = "aa"; 83 int xcnt = 0; 84 85 _DIAGASSERT(path != NULL); 86 /* doopen may be NULL */ 87 88 pid = getpid(); 89 90 /* Move to end of path and count trailing X's. */ 91 for (trv = path; *trv; ++trv) 92 if (*trv == 'X') 93 xcnt++; 94 else 95 xcnt = 0; 96 97 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 98 if (*(trv-1) == 'X') 99 *--trv = xtra[0]; 100 if (xcnt > 6 && *(trv-1) == 'X') 101 *--trv = xtra[1]; 102 103 /* Set remaining X's to pid digits with 0's to the left. */ 104 while (*--trv == 'X') { 105 *trv = (pid % 10) + '0'; 106 pid /= 10; 107 } 108 109 /* update xtra for next call. */ 110 if (xtra[0] != 'z') 111 xtra[0]++; 112 else { 113 xtra[0] = 'a'; 114 if (xtra[1] != 'z') 115 xtra[1]++; 116 else 117 xtra[1] = 'a'; 118 } 119 120 /* 121 * check the target directory; if you have six X's and it 122 * doesn't exist this runs for a *very* long time. 123 */ 124 for (start = trv + 1;; --trv) { 125 if (trv <= path) 126 break; 127 if (*trv == '/') { 128 *trv = '\0'; 129 if (stat(path, &sbuf)) 130 return (0); 131 if (!S_ISDIR(sbuf.st_mode)) { 132 errno = ENOTDIR; 133 return (0); 134 } 135 *trv = '/'; 136 break; 137 } 138 } 139 140 for (;;) { 141 if (doopen) { 142 if ((*doopen = 143 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 144 return (1); 145 if (errno != EEXIST) 146 return (0); 147 } else if (domkdir) { 148 if (mkdir(path, 0700) >= 0) 149 return (1); 150 if (errno != EEXIST) 151 return (0); 152 } else if (lstat(path, &sbuf)) 153 return (errno == ENOENT ? 1 : 0); 154 155 /* tricky little algorithm for backward compatibility */ 156 for (trv = start;;) { 157 if (!*trv) 158 return (0); 159 if (*trv == 'z') 160 *trv++ = 'a'; 161 else { 162 if (isdigit((unsigned char)*trv)) 163 *trv = 'a'; 164 else 165 ++*trv; 166 break; 167 } 168 } 169 } 170 /*NOTREACHED*/ 171 } 172 173 #endif /* !HAVE_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 174