1 /* $NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if HAVE_NBTOOL_CONFIG_H 33 #include "nbtool_config.h" 34 #endif 35 36 #if !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP 37 38 #include <sys/cdefs.h> 39 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 42 #else 43 __RCSID("$NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp $"); 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include <sys/types.h> 48 #include <sys/stat.h> 49 50 #include <assert.h> 51 #include <ctype.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <unistd.h> 57 58 #if HAVE_NBTOOL_CONFIG_H 59 #define GETTEMP gettemp 60 #else 61 #include "reentrant.h" 62 #include "local.h" 63 #define GETTEMP __gettemp 64 #endif 65 66 int 67 GETTEMP(path, doopen, domkdir) 68 char *path; 69 int *doopen; 70 int domkdir; 71 { 72 char *start, *trv; 73 struct stat sbuf; 74 u_int pid; 75 76 /* To guarantee multiple calls generate unique names even if 77 the file is not created. 676 different possibilities with 7 78 or more X's, 26 with 6 or less. */ 79 static char xtra[2] = "aa"; 80 int xcnt = 0; 81 82 _DIAGASSERT(path != NULL); 83 /* doopen may be NULL */ 84 85 pid = getpid(); 86 87 /* Move to end of path and count trailing X's. */ 88 for (trv = path; *trv; ++trv) 89 if (*trv == 'X') 90 xcnt++; 91 else 92 xcnt = 0; 93 94 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 95 if (*(trv - 1) == 'X') 96 *--trv = xtra[0]; 97 if (xcnt > 6 && *(trv - 1) == 'X') 98 *--trv = xtra[1]; 99 100 /* Set remaining X's to pid digits with 0's to the left. */ 101 while (*--trv == 'X') { 102 *trv = (pid % 10) + '0'; 103 pid /= 10; 104 } 105 106 /* update xtra for next call. */ 107 if (xtra[0] != 'z') 108 xtra[0]++; 109 else { 110 xtra[0] = 'a'; 111 if (xtra[1] != 'z') 112 xtra[1]++; 113 else 114 xtra[1] = 'a'; 115 } 116 117 /* 118 * check the target directory; if you have six X's and it 119 * doesn't exist this runs for a *very* long time. 120 */ 121 for (start = trv + 1;; --trv) { 122 if (trv <= path) 123 break; 124 if (*trv == '/') { 125 *trv = '\0'; 126 if (stat(path, &sbuf)) 127 return (0); 128 if (!S_ISDIR(sbuf.st_mode)) { 129 errno = ENOTDIR; 130 return (0); 131 } 132 *trv = '/'; 133 break; 134 } 135 } 136 137 for (;;) { 138 if (doopen) { 139 if ((*doopen = 140 open(path, O_CREAT | O_EXCL | O_RDWR, 0600)) >= 0) 141 return (1); 142 if (errno != EEXIST) 143 return (0); 144 } else if (domkdir) { 145 if (mkdir(path, 0700) >= 0) 146 return (1); 147 if (errno != EEXIST) 148 return (0); 149 } else if (lstat(path, &sbuf)) 150 return (errno == ENOENT ? 1 : 0); 151 152 /* tricky little algorithm for backward compatibility */ 153 for (trv = start;;) { 154 if (!*trv) 155 return (0); 156 if (*trv == 'z') 157 *trv++ = 'a'; 158 else { 159 if (isdigit((unsigned char)*trv)) 160 *trv = 'a'; 161 else 162 ++*trv; 163 break; 164 } 165 } 166 } 167 /*NOTREACHED*/ 168 } 169 170 #endif /* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 171