1 /* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
2 This file is part of 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
16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
17 Cambridge, MA 02139, USA. */
25 #include <sys/types.h>
35 /* Return nonzero if DIR is an existent directory. */
37 DEFUN(diraccess
, (dir
), CONST
char *dir
)
40 return __stat (dir
, &buf
) == 0 && S_ISDIR (buf
.st_mode
);
43 /* Return nonzero if FILE exists. */
45 DEFUN(exists
, (file
), CONST
char *file
)
47 /* We can stat the file even if we can't read its data. */
50 if (__stat (file
, &st
) == 0)
54 /* We report that the file exists if stat failed for a reason other
55 than nonexistence. In this case, it may or may not exist, and we
56 don't know; but reporting that it does exist will never cause any
57 trouble, while reporting that it doesn't exist when it does would
58 violate the interface of __stdio_gen_tempname. */
59 int exists
= errno
!= ENOENT
;
66 /* These are the characters used in temporary filenames. */
67 static CONST
char letters
[] =
68 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
70 /* Generate a temporary filename and return it (in a static buffer). If
71 STREAMPTR is not NULL, open a stream "w+b" on the file and set
72 *STREAMPTR to it. If DIR_SEARCH is nonzero, DIR and PFX are used as
73 described for tempnam. If not, a temporary filename in P_tmpdir with no
74 special prefix is generated. If LENPTR is not NULL, *LENPTR is set the
75 to length (including the terminating '\0') of the resultant filename,
76 which is returned. This goes through a cyclic pattern of all possible
77 filenames consisting of five decimal digits of the current pid and three
78 of the characters in `letters'. Data for tempnam and tmpnam is kept
79 separate, but when tempnam is using P_tmpdir and no prefix (i.e, it is
80 identical to tmpnam), the same data is used. Each potential filename is
81 tested for an already-existing file of the same name, and no name of an
82 existing file will be returned. When the cycle reaches its end
83 (12345ZZZ), NULL is returned. */
85 DEFUN(__stdio_gen_tempname
, (dir
, pfx
, dir_search
, lenptr
, streamptr
),
86 CONST
char *dir AND CONST
char *pfx AND
87 int dir_search AND
size_t *lenptr AND
91 static CONST
char tmpdir
[] = P_tmpdir
;
92 static size_t indices
[2];
94 static char buf
[FILENAME_MAX
];
95 static pid_t oldpid
= (pid_t
) 0;
96 pid_t pid
= __getpid();
97 register size_t len
, plen
, dlen
;
101 register CONST
char *d
= getenv ("TMPDIR");
102 if (d
!= NULL
&& !diraccess (d
))
104 if (d
== NULL
&& dir
!= NULL
&& diraccess (dir
))
106 if (d
== NULL
&& diraccess (tmpdir
))
108 if (d
== NULL
&& diraccess ("/tmp"))
122 /* Remove trailing slashes from the directory name. */
123 while (dlen
> 1 && dir
[dlen
- 1] == '/')
126 if (pfx
!= NULL
&& *pfx
!= '\0')
135 if (dir
!= tmpdir
&& !strcmp (dir
, tmpdir
))
137 idx
= &indices
[(plen
== 0 && dir
== tmpdir
) ? 1 : 0];
142 indices
[0] = indices
[1] = 0;
145 len
= dlen
+ 1 + plen
+ 5 + 3;
146 while (*idx
< ((sizeof (letters
) - 1) * (sizeof (letters
) - 1) *
147 (sizeof (letters
) - 1)))
149 const size_t i
= (*idx
)++;
151 /* Construct a file name and see if it already exists.
153 We use a single counter in *IDX to cycle each of three
154 character positions through each of 62 possible letters. */
156 if (sizeof (buf
) < len
||
157 sprintf (buf
, "%.*s/%.*s%.5d%c%c%c",
158 (int) dlen
, dir
, (int) plen
,
160 letters
[i
% (sizeof (letters
) - 1)],
161 letters
[(i
/ (sizeof (letters
) - 1))
162 % (sizeof (letters
) - 1)],
163 letters
[(i
/ ((sizeof (letters
) - 1) *
164 (sizeof (letters
) - 1)))
165 % (sizeof (letters
) - 1)]
169 if (streamptr
!= NULL
)
171 /* Try to create the file atomically. */
172 int fd
= __open (buf
, O_RDWR
|O_CREAT
|O_EXCL
, 0666);
175 /* We got a new file that did not previously exist.
176 Create a stream for it. */
179 struct _IO_FILE_plus
*fp
;
181 fp
= (struct _IO_FILE_plus
*)
182 malloc(sizeof (struct _IO_FILE_plus
));
185 /* We lost trying to create a stream (out of memory?).
186 Nothing to do but remove the file, close the descriptor,
187 and return failure. */
195 _IO_init (&fp
->file
, 0);
196 _IO_JUMPS (&fp
->file
) = &_IO_file_jumps
;
197 _IO_file_init (&fp
->file
);
198 # if !_IO_UNIFIED_JUMPTABLES
201 if (_IO_file_attach (&fp
->file
, fd
) == NULL
)
207 fp
->file
._flags
&= ~_IO_DELETE_DONT_CLOSE
;
208 fp
->file
._IO_file_flags
= 0;
210 *streamptr
= (FILE *) fp
;
212 *streamptr
= __newstream ();
213 if (*streamptr
== NULL
)
215 /* We lost trying to create a stream (out of memory?).
216 Nothing to do but remove the file, close the descriptor,
217 and return failure. */
218 const int save
= errno
;
224 (*streamptr
)->__cookie
= (PTR
) (long int) fd
;
225 (*streamptr
)->__mode
.__write
= 1;
226 (*streamptr
)->__mode
.__read
= 1;
227 (*streamptr
)->__mode
.__binary
= 1;
233 else if (exists (buf
))
236 /* If the file already existed we have continued the loop above,
237 so we only get here when we have a winning name to return. */
246 /* We got out of the loop because we ran out of combinations to try. */
247 errno
= EEXIST
; /* ? */