1 /* Utility to pick a temporary filename prefix.
2 Copyright (C) 1996, 1997, 1998, 2001, 2009, 2010
3 Free Software Foundation, Inc.
4
5 This file is part of the libiberty library.
6 Libiberty is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10
11 Libiberty is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
15
16 You should have received a copy of the GNU Library General Public
17 License along with libiberty; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
19 Boston, MA 02110-1301, USA. */
20
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24
25 #include <stdio.h> /* May get P_tmpdir. */
26 #include <sys/types.h>
27 #include <errno.h>
28 #ifdef HAVE_UNISTD_H
29 #include <unistd.h>
30 #endif
31 #ifdef HAVE_STDLIB_H
32 #include <stdlib.h>
33 #endif
34 #ifdef HAVE_STRING_H
35 #include <string.h>
36 #endif
37 #ifdef HAVE_SYS_FILE_H
38 #include <sys/file.h> /* May get R_OK, etc. on some systems. */
39 #endif
40 #if defined(_WIN32) && !defined(__CYGWIN__)
41 #include <windows.h>
42 #endif
43
44 #ifndef R_OK
45 #define R_OK 4
46 #define W_OK 2
47 #define X_OK 1
48 #endif
49
50 #include "libiberty.h"
51 extern int mkstemps (char *, int);
52
53 /* '/' works just fine on MS-DOS based systems. */
54 #ifndef DIR_SEPARATOR
55 #define DIR_SEPARATOR '/'
56 #endif
57
58 /* Name of temporary file.
59 mktemp requires 6 trailing X's. */
60 #define TEMP_FILE "ccXXXXXX"
61 #define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1)
62
63 #if !defined(_WIN32) || defined(__CYGWIN__)
64
65 /* Subroutine of choose_tmpdir.
66 If BASE is non-NULL, return it.
67 Otherwise it checks if DIR is a usable directory.
68 If success, DIR is returned.
69 Otherwise NULL is returned. */
70
71 static inline const char *try_dir (const char *, const char *);
72
73 static inline const char *
try_dir(const char * dir,const char * base)74 try_dir (const char *dir, const char *base)
75 {
76 if (base != 0)
77 return base;
78 if (dir != 0
79 && access (dir, R_OK | W_OK | X_OK) == 0)
80 return dir;
81 return 0;
82 }
83
84 static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 };
85 static const char usrtmp[] =
86 { DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 };
87 static const char vartmp[] =
88 { DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 };
89
90 #endif
91
92 static char *memoized_tmpdir;
93
94 /*
95
96 @deftypefn Replacement const char* choose_tmpdir ()
97
98 Returns a pointer to a directory path suitable for creating temporary
99 files in.
100
101 @end deftypefn
102
103 */
104
105 const char *
choose_tmpdir(void)106 choose_tmpdir (void)
107 {
108 if (!memoized_tmpdir)
109 {
110 #if !defined(_WIN32) || defined(__CYGWIN__)
111 const char *base = 0;
112 char *tmpdir;
113 unsigned int len;
114
115 #ifdef VMS
116 /* Try VMS standard temp logical. */
117 base = try_dir ("/sys$scratch", base);
118 #else
119 base = try_dir (getenv ("TMPDIR"), base);
120 base = try_dir (getenv ("TMP"), base);
121 base = try_dir (getenv ("TEMP"), base);
122 #endif
123
124 #ifdef P_tmpdir
125 /* We really want a directory name here as if concatenated with say \dir
126 we do not end up with a double \\ which defines an UNC path. */
127 if (strcmp (P_tmpdir, "\\") == 0)
128 base = try_dir ("\\.", base);
129 else
130 base = try_dir (P_tmpdir, base);
131 #endif
132
133 /* Try /var/tmp, /usr/tmp, then /tmp. */
134 base = try_dir (vartmp, base);
135 base = try_dir (usrtmp, base);
136 base = try_dir (tmp, base);
137
138 /* If all else fails, use the current directory! */
139 if (base == 0)
140 base = ".";
141 /* Append DIR_SEPARATOR to the directory we've chosen
142 and return it. */
143 len = strlen (base);
144 tmpdir = XNEWVEC (char, len + 2);
145 strcpy (tmpdir, base);
146 tmpdir[len] = DIR_SEPARATOR;
147 tmpdir[len+1] = '\0';
148 memoized_tmpdir = tmpdir;
149 #else /* defined(_WIN32) && !defined(__CYGWIN__) */
150 DWORD len;
151
152 /* Figure out how much space we need. */
153 len = GetTempPath(0, NULL);
154 if (len)
155 {
156 memoized_tmpdir = XNEWVEC (char, len);
157 if (!GetTempPath(len, memoized_tmpdir))
158 {
159 XDELETEVEC (memoized_tmpdir);
160 memoized_tmpdir = NULL;
161 }
162 }
163 if (!memoized_tmpdir)
164 /* If all else fails, use the current directory. */
165 memoized_tmpdir = xstrdup (".\\");
166 #endif /* defined(_WIN32) && !defined(__CYGWIN__) */
167 }
168
169 return memoized_tmpdir;
170 }
171
172 /*
173
174 @deftypefn Replacement char* make_temp_file (const char *@var{suffix})
175
176 Return a temporary file name (as a string) or @code{NULL} if unable to
177 create one. @var{suffix} is a suffix to append to the file name. The
178 string is @code{malloc}ed, and the temporary file has been created.
179
180 @end deftypefn
181
182 */
183
184 char *
make_temp_file(const char * suffix)185 make_temp_file (const char *suffix)
186 {
187 const char *base = choose_tmpdir ();
188 char *temp_filename;
189 int base_len, suffix_len;
190 int fd;
191
192 if (suffix == 0)
193 suffix = "";
194
195 base_len = strlen (base);
196 suffix_len = strlen (suffix);
197
198 temp_filename = XNEWVEC (char, base_len
199 + TEMP_FILE_LEN
200 + suffix_len + 1);
201 strcpy (temp_filename, base);
202 strcpy (temp_filename + base_len, TEMP_FILE);
203 strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix);
204
205 fd = mkstemps (temp_filename, suffix_len);
206 /* Mkstemps failed. It may be EPERM, ENOSPC etc. */
207 if (fd == -1)
208 {
209 fprintf (stderr, "Cannot create temporary file in %s: %s\n",
210 base, strerror (errno));
211 abort ();
212 }
213 /* We abort on failed close out of sheer paranoia. */
214 if (close (fd))
215 abort ();
216 return temp_filename;
217 }
218