1 /* Utility to pick a temporary filename prefix. 2 Copyright (C) 1996-2024 Free Software Foundation, Inc. 3 4 This file is part of the libiberty library. 5 Libiberty is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Library General Public 7 License as published by the Free Software Foundation; either 8 version 2 of the License, or (at your option) any later version. 9 10 Libiberty is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Library General Public License for more details. 14 15 You should have received a copy of the GNU Library General Public 16 License along with libiberty; see the file COPYING.LIB. If not, 17 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, 18 Boston, 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 #define WIN32_LEAN_AND_MEAN 41 #include <windows.h> 42 #endif 43 #if HAVE_SYS_STAT_H 44 #include <sys/stat.h> 45 #endif 46 47 48 #ifndef R_OK 49 #define R_OK 4 50 #define W_OK 2 51 #define X_OK 1 52 #endif 53 54 #include "libiberty.h" 55 extern int mkstemps (char *, int); 56 57 /* '/' works just fine on MS-DOS based systems. */ 58 #ifndef DIR_SEPARATOR 59 #define DIR_SEPARATOR '/' 60 #endif 61 62 /* Name of temporary file. 63 mktemp requires 6 trailing X's. */ 64 #define TEMP_FILE "XXXXXX" 65 #define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1) 66 67 #if !defined(_WIN32) || defined(__CYGWIN__) 68 69 /* Subroutine of choose_tmpdir. 70 If BASE is non-NULL, return it. 71 Otherwise it checks if DIR is a usable directory. 72 If success, DIR is returned. 73 Otherwise NULL is returned. */ 74 75 static inline const char *try_dir (const char *, const char *); 76 77 static inline const char * 78 try_dir (const char *dir, const char *base) 79 { 80 if (base != 0) 81 return base; 82 if (dir != 0 83 && access (dir, R_OK | W_OK | X_OK) == 0) 84 { 85 /* Check to make sure dir is actually a directory. */ 86 #ifdef S_ISDIR 87 struct stat s; 88 if (stat (dir, &s)) 89 return NULL; 90 if (!S_ISDIR (s.st_mode)) 91 return NULL; 92 #endif 93 return dir; 94 } 95 return 0; 96 } 97 98 static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 }; 99 static const char usrtmp[] = 100 { DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 101 static const char vartmp[] = 102 { DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 103 104 #endif 105 106 static char *memoized_tmpdir; 107 108 /* 109 110 @deftypefn Replacement const char* choose_tmpdir () 111 112 Returns a pointer to a directory path suitable for creating temporary 113 files in. 114 115 @end deftypefn 116 117 */ 118 119 const char * 120 choose_tmpdir (void) 121 { 122 if (!memoized_tmpdir) 123 { 124 #if !defined(_WIN32) || defined(__CYGWIN__) 125 const char *base = 0; 126 char *tmpdir; 127 unsigned int len; 128 129 #ifdef VMS 130 /* Try VMS standard temp logical. */ 131 base = try_dir ("/sys$scratch", base); 132 #else 133 base = try_dir (getenv ("TMPDIR"), base); 134 base = try_dir (getenv ("TMP"), base); 135 base = try_dir (getenv ("TEMP"), base); 136 #endif 137 138 #ifdef P_tmpdir 139 /* We really want a directory name here as if concatenated with say \dir 140 we do not end up with a double \\ which defines an UNC path. */ 141 if (strcmp (P_tmpdir, "\\") == 0) 142 base = try_dir ("\\.", base); 143 else 144 base = try_dir (P_tmpdir, base); 145 #endif 146 147 /* Try /tmp, /var/tmp, then /usr/tmp. */ 148 base = try_dir (tmp, base); 149 base = try_dir (vartmp, base); 150 base = try_dir (usrtmp, base); 151 152 /* If all else fails, use the current directory! */ 153 if (base == 0) 154 base = "."; 155 /* Append DIR_SEPARATOR to the directory we've chosen 156 and return it. */ 157 len = strlen (base); 158 tmpdir = XNEWVEC (char, len + 2); 159 strcpy (tmpdir, base); 160 tmpdir[len] = DIR_SEPARATOR; 161 tmpdir[len+1] = '\0'; 162 memoized_tmpdir = tmpdir; 163 #else /* defined(_WIN32) && !defined(__CYGWIN__) */ 164 DWORD len; 165 166 /* Figure out how much space we need. */ 167 len = GetTempPath(0, NULL); 168 if (len) 169 { 170 memoized_tmpdir = XNEWVEC (char, len); 171 if (!GetTempPath(len, memoized_tmpdir)) 172 { 173 XDELETEVEC (memoized_tmpdir); 174 memoized_tmpdir = NULL; 175 } 176 } 177 if (!memoized_tmpdir) 178 /* If all else fails, use the current directory. */ 179 memoized_tmpdir = xstrdup (".\\"); 180 #endif /* defined(_WIN32) && !defined(__CYGWIN__) */ 181 } 182 183 return memoized_tmpdir; 184 } 185 186 /* 187 188 @deftypefn Replacement char* make_temp_file (const char *@var{suffix}) 189 190 Return a temporary file name (as a string) or @code{NULL} if unable to 191 create one. @var{suffix} is a suffix to append to the file name. The 192 string is @code{malloc}ed, and the temporary file has been created. 193 194 @end deftypefn 195 196 */ 197 198 char * 199 make_temp_file_with_prefix (const char *prefix, const char *suffix) 200 { 201 const char *base = choose_tmpdir (); 202 char *temp_filename; 203 int base_len, suffix_len, prefix_len; 204 int fd; 205 206 if (prefix == 0) 207 prefix = "cc"; 208 209 if (suffix == 0) 210 suffix = ""; 211 212 base_len = strlen (base); 213 prefix_len = strlen (prefix); 214 suffix_len = strlen (suffix); 215 216 temp_filename = XNEWVEC (char, base_len 217 + TEMP_FILE_LEN 218 + suffix_len 219 + prefix_len + 1); 220 strcpy (temp_filename, base); 221 strcpy (temp_filename + base_len, prefix); 222 strcpy (temp_filename + base_len + prefix_len, TEMP_FILE); 223 strcpy (temp_filename + base_len + prefix_len + TEMP_FILE_LEN, suffix); 224 225 fd = mkstemps (temp_filename, suffix_len); 226 /* Mkstemps failed. It may be EPERM, ENOSPC etc. */ 227 if (fd == -1) 228 { 229 fprintf (stderr, "Cannot create temporary file in %s: %s\n", 230 base, strerror (errno)); 231 abort (); 232 } 233 /* We abort on failed close out of sheer paranoia. */ 234 if (close (fd)) 235 abort (); 236 return temp_filename; 237 } 238 239 char * 240 make_temp_file (const char *suffix) 241 { 242 return make_temp_file_with_prefix (NULL, suffix); 243 } 244