1 /* Utility to pick a temporary filename prefix. 2 Copyright (C) 1996-2018 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 #include <windows.h> 41 #endif 42 43 #ifndef R_OK 44 #define R_OK 4 45 #define W_OK 2 46 #define X_OK 1 47 #endif 48 49 #include "libiberty.h" 50 extern int mkstemps (char *, int); 51 52 /* '/' works just fine on MS-DOS based systems. */ 53 #ifndef DIR_SEPARATOR 54 #define DIR_SEPARATOR '/' 55 #endif 56 57 /* Name of temporary file. 58 mktemp requires 6 trailing X's. */ 59 #define TEMP_FILE "ccXXXXXX" 60 #define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1) 61 62 #if !defined(_WIN32) || defined(__CYGWIN__) 63 64 /* Subroutine of choose_tmpdir. 65 If BASE is non-NULL, return it. 66 Otherwise it checks if DIR is a usable directory. 67 If success, DIR is returned. 68 Otherwise NULL is returned. */ 69 70 static inline const char *try_dir (const char *, const char *); 71 72 static inline const char * 73 try_dir (const char *dir, const char *base) 74 { 75 if (base != 0) 76 return base; 77 if (dir != 0 78 && access (dir, R_OK | W_OK | X_OK) == 0) 79 return dir; 80 return 0; 81 } 82 83 static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 }; 84 static const char usrtmp[] = 85 { DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 86 static const char vartmp[] = 87 { DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 88 89 #endif 90 91 static char *memoized_tmpdir; 92 93 /* 94 95 @deftypefn Replacement const char* choose_tmpdir () 96 97 Returns a pointer to a directory path suitable for creating temporary 98 files in. 99 100 @end deftypefn 101 102 */ 103 104 const char * 105 choose_tmpdir (void) 106 { 107 if (!memoized_tmpdir) 108 { 109 #if !defined(_WIN32) || defined(__CYGWIN__) 110 const char *base = 0; 111 char *tmpdir; 112 unsigned int len; 113 114 #ifdef VMS 115 /* Try VMS standard temp logical. */ 116 base = try_dir ("/sys$scratch", base); 117 #else 118 base = try_dir (getenv ("TMPDIR"), base); 119 base = try_dir (getenv ("TMP"), base); 120 base = try_dir (getenv ("TEMP"), base); 121 #endif 122 123 #ifdef P_tmpdir 124 /* We really want a directory name here as if concatenated with say \dir 125 we do not end up with a double \\ which defines an UNC path. */ 126 if (strcmp (P_tmpdir, "\\") == 0) 127 base = try_dir ("\\.", base); 128 else 129 base = try_dir (P_tmpdir, base); 130 #endif 131 132 /* Try /var/tmp, /usr/tmp, then /tmp. */ 133 base = try_dir (vartmp, base); 134 base = try_dir (usrtmp, base); 135 base = try_dir (tmp, base); 136 137 /* If all else fails, use the current directory! */ 138 if (base == 0) 139 base = "."; 140 /* Append DIR_SEPARATOR to the directory we've chosen 141 and return it. */ 142 len = strlen (base); 143 tmpdir = XNEWVEC (char, len + 2); 144 strcpy (tmpdir, base); 145 tmpdir[len] = DIR_SEPARATOR; 146 tmpdir[len+1] = '\0'; 147 memoized_tmpdir = tmpdir; 148 #else /* defined(_WIN32) && !defined(__CYGWIN__) */ 149 DWORD len; 150 151 /* Figure out how much space we need. */ 152 len = GetTempPath(0, NULL); 153 if (len) 154 { 155 memoized_tmpdir = XNEWVEC (char, len); 156 if (!GetTempPath(len, memoized_tmpdir)) 157 { 158 XDELETEVEC (memoized_tmpdir); 159 memoized_tmpdir = NULL; 160 } 161 } 162 if (!memoized_tmpdir) 163 /* If all else fails, use the current directory. */ 164 memoized_tmpdir = xstrdup (".\\"); 165 #endif /* defined(_WIN32) && !defined(__CYGWIN__) */ 166 } 167 168 return memoized_tmpdir; 169 } 170 171 /* 172 173 @deftypefn Replacement char* make_temp_file (const char *@var{suffix}) 174 175 Return a temporary file name (as a string) or @code{NULL} if unable to 176 create one. @var{suffix} is a suffix to append to the file name. The 177 string is @code{malloc}ed, and the temporary file has been created. 178 179 @end deftypefn 180 181 */ 182 183 char * 184 make_temp_file (const char *suffix) 185 { 186 const char *base = choose_tmpdir (); 187 char *temp_filename; 188 int base_len, suffix_len; 189 int fd; 190 191 if (suffix == 0) 192 suffix = ""; 193 194 base_len = strlen (base); 195 suffix_len = strlen (suffix); 196 197 temp_filename = XNEWVEC (char, base_len 198 + TEMP_FILE_LEN 199 + suffix_len + 1); 200 strcpy (temp_filename, base); 201 strcpy (temp_filename + base_len, TEMP_FILE); 202 strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix); 203 204 fd = mkstemps (temp_filename, suffix_len); 205 /* Mkstemps failed. It may be EPERM, ENOSPC etc. */ 206 if (fd == -1) 207 { 208 fprintf (stderr, "Cannot create temporary file in %s: %s\n", 209 base, strerror (errno)); 210 abort (); 211 } 212 /* We abort on failed close out of sheer paranoia. */ 213 if (close (fd)) 214 abort (); 215 return temp_filename; 216 } 217