1 /* Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc.
2 This file is derived from mkstemp.c from the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
21 #include <sys/types.h>
30 #ifdef HAVE_SYS_TIME_H
34 /* We need to provide a type for gcc_uint64_t. */
36 __extension__
typedef unsigned long long gcc_uint64_t
;
38 typedef unsigned long gcc_uint64_t
;
47 @deftypefn Replacement int mkstemps (char *@var{template}, int @var{suffix_len})
49 Generate a unique temporary file name from @var{template}.
50 @var{template} has the form:
53 @var{path}/ccXXXXXX@var{suffix}
56 @var{suffix_len} tells us how long @var{suffix} is (it can be zero
57 length). The last six characters of @var{template} before @var{suffix}
58 must be @samp{XXXXXX}; they are replaced with a string that makes the
59 filename unique. Returns a file descriptor open on the file for
67 mkstemps (template, suffix_len
)
71 static const char letters
[]
72 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
73 static gcc_uint64_t value
;
74 #ifdef HAVE_GETTIMEOFDAY
81 len
= strlen (template);
83 if ((int) len
< 6 + suffix_len
84 || strncmp (&template[len
- 6 - suffix_len
], "XXXXXX", 6))
89 XXXXXX
= &template[len
- 6 - suffix_len
];
91 #ifdef HAVE_GETTIMEOFDAY
92 /* Get some more or less random data. */
93 gettimeofday (&tv
, NULL
);
94 value
+= ((gcc_uint64_t
) tv
.tv_usec
<< 16) ^ tv
.tv_sec
^ getpid ();
99 for (count
= 0; count
< TMP_MAX
; ++count
)
101 gcc_uint64_t v
= value
;
104 /* Fill in the random bits. */
105 XXXXXX
[0] = letters
[v
% 62];
107 XXXXXX
[1] = letters
[v
% 62];
109 XXXXXX
[2] = letters
[v
% 62];
111 XXXXXX
[3] = letters
[v
% 62];
113 XXXXXX
[4] = letters
[v
% 62];
115 XXXXXX
[5] = letters
[v
% 62];
118 fd
= open (template, O_RDWR
|O_CREAT
|O_EXCL
, 0600, "fop=tmd");
120 fd
= open (template, O_RDWR
|O_CREAT
|O_EXCL
, 0600);
123 /* The file does not exist. */
126 /* This is a random value. It is only necessary that the next
127 TMP_MAX values generated by adding 7777 to VALUE are different
128 with (module 2^32). */
132 /* We return the null string if we can't find a unique file name. */