| 1 | /* Utility to pick a temporary filename prefix. |
| 2 | Copyright (C) 1996, 1997, 1998, 2001 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 | #ifdef HAVE_UNISTD_H |
| 27 | #include <unistd.h> |
| 28 | #endif |
| 29 | #ifdef HAVE_STDLIB_H |
| 30 | #include <stdlib.h> |
| 31 | #endif |
| 32 | #ifdef HAVE_STRING_H |
| 33 | #include <string.h> |
| 34 | #endif |
| 35 | #ifdef HAVE_SYS_FILE_H |
| 36 | #include <sys/file.h> /* May get R_OK, etc. on some systems. */ |
| 37 | #endif |
| 38 | |
| 39 | #ifndef R_OK |
| 40 | #define R_OK 4 |
| 41 | #define W_OK 2 |
| 42 | #define X_OK 1 |
| 43 | #endif |
| 44 | |
| 45 | #include "libiberty.h" |
| 46 | extern int mkstemps (char *, int); |
| 47 | |
| 48 | /* '/' works just fine on MS-DOS based systems. */ |
| 49 | #ifndef DIR_SEPARATOR |
| 50 | #define DIR_SEPARATOR '/' |
| 51 | #endif |
| 52 | |
| 53 | /* Name of temporary file. |
| 54 | mktemp requires 6 trailing X's. */ |
| 55 | #define TEMP_FILE "ccXXXXXX" |
| 56 | #define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1) |
| 57 | |
| 58 | /* Subroutine of choose_tmpdir. |
| 59 | If BASE is non-NULL, return it. |
| 60 | Otherwise it checks if DIR is a usable directory. |
| 61 | If success, DIR is returned. |
| 62 | Otherwise NULL is returned. */ |
| 63 | |
| 64 | static inline const char *try_dir (const char *, const char *); |
| 65 | |
| 66 | static inline const char * |
| 67 | try_dir (const char *dir, const char *base) |
| 68 | { |
| 69 | if (base != 0) |
| 70 | return base; |
| 71 | if (dir != 0 |
| 72 | && access (dir, R_OK | W_OK | X_OK) == 0) |
| 73 | return dir; |
| 74 | return 0; |
| 75 | } |
| 76 | |
| 77 | static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 }; |
| 78 | static const char usrtmp[] = |
| 79 | { DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; |
| 80 | static const char vartmp[] = |
| 81 | { DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; |
| 82 | |
| 83 | static char *memoized_tmpdir; |
| 84 | |
| 85 | /* |
| 86 | |
| 87 | @deftypefn Replacement char* choose_tmpdir () |
| 88 | |
| 89 | Returns a pointer to a directory path suitable for creating temporary |
| 90 | files in. |
| 91 | |
| 92 | @end deftypefn |
| 93 | |
| 94 | */ |
| 95 | |
| 96 | char * |
| 97 | choose_tmpdir (void) |
| 98 | { |
| 99 | const char *base = 0; |
| 100 | char *tmpdir; |
| 101 | unsigned int len; |
| 102 | |
| 103 | if (memoized_tmpdir) |
| 104 | return memoized_tmpdir; |
| 105 | |
| 106 | base = try_dir (getenv ("TMPDIR"), base); |
| 107 | base = try_dir (getenv ("TMP"), base); |
| 108 | base = try_dir (getenv ("TEMP"), base); |
| 109 | |
| 110 | #ifdef P_tmpdir |
| 111 | base = try_dir (P_tmpdir, base); |
| 112 | #endif |
| 113 | |
| 114 | /* Try /var/tmp, /usr/tmp, then /tmp. */ |
| 115 | base = try_dir (vartmp, base); |
| 116 | base = try_dir (usrtmp, base); |
| 117 | base = try_dir (tmp, base); |
| 118 | |
| 119 | /* If all else fails, use the current directory! */ |
| 120 | if (base == 0) |
| 121 | base = "."; |
| 122 | |
| 123 | /* Append DIR_SEPARATOR to the directory we've chosen |
| 124 | and return it. */ |
| 125 | len = strlen (base); |
| 126 | tmpdir = XNEWVEC (char, len + 2); |
| 127 | strcpy (tmpdir, base); |
| 128 | tmpdir[len] = DIR_SEPARATOR; |
| 129 | tmpdir[len+1] = '\0'; |
| 130 | |
| 131 | memoized_tmpdir = tmpdir; |
| 132 | return tmpdir; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | |
| 137 | @deftypefn Replacement char* make_temp_file (const char *@var{suffix}) |
| 138 | |
| 139 | Return a temporary file name (as a string) or @code{NULL} if unable to |
| 140 | create one. @var{suffix} is a suffix to append to the file name. The |
| 141 | string is @code{malloc}ed, and the temporary file has been created. |
| 142 | |
| 143 | @end deftypefn |
| 144 | |
| 145 | */ |
| 146 | |
| 147 | char * |
| 148 | make_temp_file (const char *suffix) |
| 149 | { |
| 150 | const char *base = choose_tmpdir (); |
| 151 | char *temp_filename; |
| 152 | int base_len, suffix_len; |
| 153 | int fd; |
| 154 | |
| 155 | if (suffix == 0) |
| 156 | suffix = ""; |
| 157 | |
| 158 | base_len = strlen (base); |
| 159 | suffix_len = strlen (suffix); |
| 160 | |
| 161 | temp_filename = XNEWVEC (char, base_len |
| 162 | + TEMP_FILE_LEN |
| 163 | + suffix_len + 1); |
| 164 | strcpy (temp_filename, base); |
| 165 | strcpy (temp_filename + base_len, TEMP_FILE); |
| 166 | strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix); |
| 167 | |
| 168 | fd = mkstemps (temp_filename, suffix_len); |
| 169 | /* If mkstemps failed, then something bad is happening. Maybe we should |
| 170 | issue a message about a possible security attack in progress? */ |
| 171 | if (fd == -1) |
| 172 | abort (); |
| 173 | /* Similarly if we can not close the file. */ |
| 174 | if (close (fd)) |
| 175 | abort (); |
| 176 | return temp_filename; |
| 177 | } |