1/* Utility to pick a temporary filename prefix. 2 Copyright (C) 1996-2022 Free Software Foundation, Inc. 3 4This file is part of the libiberty library. 5Libiberty is free software; you can redistribute it and/or 6modify it under the terms of the GNU Library General Public 7License as published by the Free Software Foundation; either 8version 2 of the License, or (at your option) any later version. 9 10Libiberty is distributed in the hope that it will be useful, 11but WITHOUT ANY WARRANTY; without even the implied warranty of 12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13Library General Public License for more details. 14 15You should have received a copy of the GNU Library General Public 16License along with libiberty; see the file COPYING.LIB. If not, 17write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, 18Boston, MA 02110-1301, USA. */ 19 20#ifdef HAVE_CONFIG_H 21#include "config.h" 22#endif 23 24#include <stdio.h> /* May get P_tmpdir. */ 25#include <sys/types.h> 26#include <errno.h> 27#ifdef HAVE_UNISTD_H 28#include <unistd.h> 29#endif 30#ifdef HAVE_STDLIB_H 31#include <stdlib.h> 32#endif 33#ifdef HAVE_STRING_H 34#include <string.h> 35#endif 36#ifdef HAVE_SYS_FILE_H 37#include <sys/file.h> /* May get R_OK, etc. on some systems. */ 38#endif 39#if defined(_WIN32) && !defined(__CYGWIN__) 40#include <windows.h> 41#endif 42#if HAVE_SYS_STAT_H 43#include <sys/stat.h> 44#endif 45 46 47#ifndef R_OK 48#define R_OK 4 49#define W_OK 2 50#define X_OK 1 51#endif 52 53#include "libiberty.h" 54extern int mkstemps (char *, int); 55 56/* '/' works just fine on MS-DOS based systems. */ 57#ifndef DIR_SEPARATOR 58#define DIR_SEPARATOR '/' 59#endif 60 61/* Name of temporary file. 62 mktemp requires 6 trailing X's. */ 63#define TEMP_FILE "XXXXXX" 64#define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1) 65 66#if !defined(_WIN32) || defined(__CYGWIN__) 67 68/* Subroutine of choose_tmpdir. 69 If BASE is non-NULL, return it. 70 Otherwise it checks if DIR is a usable directory. 71 If success, DIR is returned. 72 Otherwise NULL is returned. */ 73 74static inline const char *try_dir (const char *, const char *); 75 76static inline const char * 77try_dir (const char *dir, const char *base) 78{ 79 if (base != 0) 80 return base; 81 if (dir != 0 82 && access (dir, R_OK | W_OK | X_OK) == 0) 83 { 84 /* Check to make sure dir is actually a directory. */ 85#ifdef S_ISDIR 86 struct stat s; 87 if (stat (dir, &s)) 88 return NULL; 89 if (!S_ISDIR (s.st_mode)) 90 return NULL; 91#endif 92 return dir; 93 } 94 return 0; 95} 96 97static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 }; 98static const char usrtmp[] = 99{ DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 100static const char vartmp[] = 101{ DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 102 103#endif 104 105static char *memoized_tmpdir; 106 107/* 108 109@deftypefn Replacement const char* choose_tmpdir () 110 111Returns a pointer to a directory path suitable for creating temporary 112files in. 113 114@end deftypefn 115 116*/ 117 118const char * 119choose_tmpdir (void) 120{ 121 if (!memoized_tmpdir) 122 { 123#if !defined(_WIN32) || defined(__CYGWIN__) 124 const char *base = 0; 125 char *tmpdir; 126 unsigned int len; 127 128#ifdef VMS 129 /* Try VMS standard temp logical. */ 130 base = try_dir ("/sys$scratch", base); 131#else 132 base = try_dir (getenv ("TMPDIR"), base); 133 base = try_dir (getenv ("TMP"), base); 134 base = try_dir (getenv ("TEMP"), base); 135#endif 136 137#ifdef P_tmpdir 138 /* We really want a directory name here as if concatenated with say \dir 139 we do not end up with a double \\ which defines an UNC path. */ 140 if (strcmp (P_tmpdir, "\\") == 0) 141 base = try_dir ("\\.", base); 142 else 143 base = try_dir (P_tmpdir, base); 144#endif 145 146 /* Try /tmp, /var/tmp, then /usr/tmp. */ 147 base = try_dir (tmp, base); 148 base = try_dir (vartmp, base); 149 base = try_dir (usrtmp, base); 150 151 /* If all else fails, use the current directory! */ 152 if (base == 0) 153 base = "."; 154 /* Append DIR_SEPARATOR to the directory we've chosen 155 and return it. */ 156 len = strlen (base); 157 tmpdir = XNEWVEC (char, len + 2); 158 strcpy (tmpdir, base); 159 tmpdir[len] = DIR_SEPARATOR; 160 tmpdir[len+1] = '\0'; 161 memoized_tmpdir = tmpdir; 162#else /* defined(_WIN32) && !defined(__CYGWIN__) */ 163 DWORD len; 164 165 /* Figure out how much space we need. */ 166 len = GetTempPath(0, NULL); 167 if (len) 168 { 169 memoized_tmpdir = XNEWVEC (char, len); 170 if (!GetTempPath(len, memoized_tmpdir)) 171 { 172 XDELETEVEC (memoized_tmpdir); 173 memoized_tmpdir = NULL; 174 } 175 } 176 if (!memoized_tmpdir) 177 /* If all else fails, use the current directory. */ 178 memoized_tmpdir = xstrdup (".\\"); 179#endif /* defined(_WIN32) && !defined(__CYGWIN__) */ 180 } 181 182 return memoized_tmpdir; 183} 184 185/* 186 187@deftypefn Replacement char* make_temp_file (const char *@var{suffix}) 188 189Return a temporary file name (as a string) or @code{NULL} if unable to 190create one. @var{suffix} is a suffix to append to the file name. The 191string is @code{malloc}ed, and the temporary file has been created. 192 193@end deftypefn 194 195*/ 196 197char * 198make_temp_file_with_prefix (const char *prefix, const char *suffix) 199{ 200 const char *base = choose_tmpdir (); 201 char *temp_filename; 202 int base_len, suffix_len, prefix_len; 203 int fd; 204 205 if (prefix == 0) 206 prefix = "cc"; 207 208 if (suffix == 0) 209 suffix = ""; 210 211 base_len = strlen (base); 212 prefix_len = strlen (prefix); 213 suffix_len = strlen (suffix); 214 215 temp_filename = XNEWVEC (char, base_len 216 + TEMP_FILE_LEN 217 + suffix_len 218 + prefix_len + 1); 219 strcpy (temp_filename, base); 220 strcpy (temp_filename + base_len, prefix); 221 strcpy (temp_filename + base_len + prefix_len, TEMP_FILE); 222 strcpy (temp_filename + base_len + prefix_len + TEMP_FILE_LEN, suffix); 223 224 fd = mkstemps (temp_filename, suffix_len); 225 /* Mkstemps failed. It may be EPERM, ENOSPC etc. */ 226 if (fd == -1) 227 { 228 fprintf (stderr, "Cannot create temporary file in %s: %s\n", 229 base, strerror (errno)); 230 abort (); 231 } 232 /* We abort on failed close out of sheer paranoia. */ 233 if (close (fd)) 234 abort (); 235 return temp_filename; 236} 237 238char * 239make_temp_file (const char *suffix) 240{ 241 return make_temp_file_with_prefix (NULL, suffix); 242} 243