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., 59 Temple Place - Suite 330, 18 Boston, MA 02111-1307, 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 PARAMS ((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 PARAMS ((const char *, const char *)); 65 66 static inline const char * 67 try (dir, base) 68 const char *dir, *base; 69 { 70 if (base != 0) 71 return base; 72 if (dir != 0 73 && access (dir, R_OK | W_OK | X_OK) == 0) 74 return dir; 75 return 0; 76 } 77 78 static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 }; 79 static const char usrtmp[] = 80 { DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 81 static const char vartmp[] = 82 { DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 }; 83 84 static char *memoized_tmpdir; 85 86 /* 87 88 @deftypefn Replacement char* choose_tmpdir () 89 90 Returns a pointer to a directory path suitable for creating temporary 91 files in. 92 93 @end deftypefn 94 95 */ 96 97 char * 98 choose_tmpdir () 99 { 100 const char *base = 0; 101 char *tmpdir; 102 unsigned int len; 103 104 if (memoized_tmpdir) 105 return memoized_tmpdir; 106 107 base = try (getenv ("TMPDIR"), base); 108 base = try (getenv ("TMP"), base); 109 base = try (getenv ("TEMP"), base); 110 111 #ifdef P_tmpdir 112 base = try (P_tmpdir, base); 113 #endif 114 115 /* Try /var/tmp, /usr/tmp, then /tmp. */ 116 base = try (vartmp, base); 117 base = try (usrtmp, base); 118 base = try (tmp, base); 119 120 /* If all else fails, use the current directory! */ 121 if (base == 0) 122 base = "."; 123 124 /* Append DIR_SEPARATOR to the directory we've chosen 125 and return it. */ 126 len = strlen (base); 127 tmpdir = xmalloc (len + 2); 128 strcpy (tmpdir, base); 129 tmpdir[len] = DIR_SEPARATOR; 130 tmpdir[len+1] = '\0'; 131 132 memoized_tmpdir = tmpdir; 133 return tmpdir; 134 } 135 136 /* 137 138 @deftypefn Replacement char* make_temp_file (const char *@var{suffix}) 139 140 Return a temporary file name (as a string) or @code{NULL} if unable to 141 create one. @var{suffix} is a suffix to append to the file name. The 142 string is @code{malloc}ed, and the temporary file has been created. 143 144 @end deftypefn 145 146 */ 147 148 char * 149 make_temp_file (suffix) 150 const char *suffix; 151 { 152 const char *base = choose_tmpdir (); 153 char *temp_filename; 154 int base_len, suffix_len; 155 int fd; 156 157 if (suffix == 0) 158 suffix = ""; 159 160 base_len = strlen (base); 161 suffix_len = strlen (suffix); 162 163 temp_filename = xmalloc (base_len 164 + TEMP_FILE_LEN 165 + suffix_len + 1); 166 strcpy (temp_filename, base); 167 strcpy (temp_filename + base_len, TEMP_FILE); 168 strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix); 169 170 fd = mkstemps (temp_filename, suffix_len); 171 /* If mkstemps failed, then something bad is happening. Maybe we should 172 issue a message about a possible security attack in progress? */ 173 if (fd == -1) 174 abort (); 175 /* Similarly if we can not close the file. */ 176 if (close (fd)) 177 abort (); 178 return temp_filename; 179 } 180