1 /* $NetBSD: gettemp.c,v 1.9 2003/01/18 11:29:55 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 1.9 2003/01/18 11:29:55 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 #include "reentrant.h" 63 64 #if HAVE_CONFIG_H 65 #define GETTEMP gettemp 66 #else 67 #include "local.h" 68 #define GETTEMP __gettemp 69 #endif 70 71 int 72 GETTEMP(path, doopen, domkdir) 73 char *path; 74 int *doopen; 75 int domkdir; 76 { 77 char *start, *trv; 78 struct stat sbuf; 79 u_int pid; 80 81 /* To guarantee multiple calls generate unique names even if 82 the file is not created. 676 different possibilities with 7 83 or more X's, 26 with 6 or less. */ 84 static char xtra[2] = "aa"; 85 int xcnt = 0; 86 87 _DIAGASSERT(path != NULL); 88 /* doopen may be NULL */ 89 90 pid = getpid(); 91 92 /* Move to end of path and count trailing X's. */ 93 for (trv = path; *trv; ++trv) 94 if (*trv == 'X') 95 xcnt++; 96 else 97 xcnt = 0; 98 99 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 100 if (*(trv-1) == 'X') 101 *--trv = xtra[0]; 102 if (xcnt > 6 && *(trv-1) == 'X') 103 *--trv = xtra[1]; 104 105 /* Set remaining X's to pid digits with 0's to the left. */ 106 while (*--trv == 'X') { 107 *trv = (pid % 10) + '0'; 108 pid /= 10; 109 } 110 111 /* update xtra for next call. */ 112 if (xtra[0] != 'z') 113 xtra[0]++; 114 else { 115 xtra[0] = 'a'; 116 if (xtra[1] != 'z') 117 xtra[1]++; 118 else 119 xtra[1] = 'a'; 120 } 121 122 /* 123 * check the target directory; if you have six X's and it 124 * doesn't exist this runs for a *very* long time. 125 */ 126 for (start = trv + 1;; --trv) { 127 if (trv <= path) 128 break; 129 if (*trv == '/') { 130 *trv = '\0'; 131 if (stat(path, &sbuf)) 132 return (0); 133 if (!S_ISDIR(sbuf.st_mode)) { 134 errno = ENOTDIR; 135 return (0); 136 } 137 *trv = '/'; 138 break; 139 } 140 } 141 142 for (;;) { 143 if (doopen) { 144 if ((*doopen = 145 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 146 return (1); 147 if (errno != EEXIST) 148 return (0); 149 } else if (domkdir) { 150 if (mkdir(path, 0700) >= 0) 151 return (1); 152 if (errno != EEXIST) 153 return (0); 154 } else if (lstat(path, &sbuf)) 155 return (errno == ENOENT ? 1 : 0); 156 157 /* tricky little algorithm for backward compatibility */ 158 for (trv = start;;) { 159 if (!*trv) 160 return (0); 161 if (*trv == 'z') 162 *trv++ = 'a'; 163 else { 164 if (isdigit((unsigned char)*trv)) 165 *trv = 'a'; 166 else 167 ++*trv; 168 break; 169 } 170 } 171 } 172 /*NOTREACHED*/ 173 } 174 175 #endif /* !HAVE_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 176