1 /* $NetBSD: gettemp.c,v 1.10 2003/08/07 16:43:27 agc 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_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #if !HAVE_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 1.10 2003/08/07 16:43:27 agc 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 #include "reentrant.h" 59 60 #if HAVE_CONFIG_H 61 #define GETTEMP gettemp 62 #else 63 #include "local.h" 64 #define GETTEMP __gettemp 65 #endif 66 67 int 68 GETTEMP(path, doopen, domkdir) 69 char *path; 70 int *doopen; 71 int domkdir; 72 { 73 char *start, *trv; 74 struct stat sbuf; 75 u_int pid; 76 77 /* To guarantee multiple calls generate unique names even if 78 the file is not created. 676 different possibilities with 7 79 or more X's, 26 with 6 or less. */ 80 static char xtra[2] = "aa"; 81 int xcnt = 0; 82 83 _DIAGASSERT(path != NULL); 84 /* doopen may be NULL */ 85 86 pid = getpid(); 87 88 /* Move to end of path and count trailing X's. */ 89 for (trv = path; *trv; ++trv) 90 if (*trv == 'X') 91 xcnt++; 92 else 93 xcnt = 0; 94 95 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 96 if (*(trv-1) == 'X') 97 *--trv = xtra[0]; 98 if (xcnt > 6 && *(trv-1) == 'X') 99 *--trv = xtra[1]; 100 101 /* Set remaining X's to pid digits with 0's to the left. */ 102 while (*--trv == 'X') { 103 *trv = (pid % 10) + '0'; 104 pid /= 10; 105 } 106 107 /* update xtra for next call. */ 108 if (xtra[0] != 'z') 109 xtra[0]++; 110 else { 111 xtra[0] = 'a'; 112 if (xtra[1] != 'z') 113 xtra[1]++; 114 else 115 xtra[1] = 'a'; 116 } 117 118 /* 119 * check the target directory; if you have six X's and it 120 * doesn't exist this runs for a *very* long time. 121 */ 122 for (start = trv + 1;; --trv) { 123 if (trv <= path) 124 break; 125 if (*trv == '/') { 126 *trv = '\0'; 127 if (stat(path, &sbuf)) 128 return (0); 129 if (!S_ISDIR(sbuf.st_mode)) { 130 errno = ENOTDIR; 131 return (0); 132 } 133 *trv = '/'; 134 break; 135 } 136 } 137 138 for (;;) { 139 if (doopen) { 140 if ((*doopen = 141 open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 142 return (1); 143 if (errno != EEXIST) 144 return (0); 145 } else if (domkdir) { 146 if (mkdir(path, 0700) >= 0) 147 return (1); 148 if (errno != EEXIST) 149 return (0); 150 } else if (lstat(path, &sbuf)) 151 return (errno == ENOENT ? 1 : 0); 152 153 /* tricky little algorithm for backward compatibility */ 154 for (trv = start;;) { 155 if (!*trv) 156 return (0); 157 if (*trv == 'z') 158 *trv++ = 'a'; 159 else { 160 if (isdigit((unsigned char)*trv)) 161 *trv = 'a'; 162 else 163 ++*trv; 164 break; 165 } 166 } 167 } 168 /*NOTREACHED*/ 169 } 170 171 #endif /* !HAVE_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 172