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 } 178