This implementation is better than what one usually finds in libc.
--hniksic */
+static unsigned int temp_name_rand;
+
DEFUN ("make-temp-name", Fmake_temp_name, 1, 1, 0, /*
-Generate temporary file name starting with PREFIX.
+Generate a temporary file name starting with PREFIX.
The Emacs process number forms part of the result, so there is no
danger of generating a name being used by another process.
*/
(prefix))
{
- static char tbl[64] = {
+ static const char tbl[64] =
+ {
'A','B','C','D','E','F','G','H',
'I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X',
'g','h','i','j','k','l','m','n',
'o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3',
- '4','5','6','7','8','9','-','_' };
- static unsigned count, count_initialized_p;
+ '4','5','6','7','8','9','-','_'
+ };
Lisp_Object val;
Bytecount len;
Bufbyte *p, *data;
- unsigned pid;
CHECK_STRING (prefix);
/* VAL is created by adding 6 characters to PREFIX. The first three
are the PID of this process, in base 64, and the second three are
- incremented if the file already exists. This ensures 262144
- unique file names per PID per PREFIX. */
+ a pseudo-random number seeded from process startup time. This
+ ensures 262144 unique file names per PID per PREFIX per machine. */
- pid = (unsigned)getpid ();
- *p++ = tbl[pid & 63], pid >>= 6;
- *p++ = tbl[pid & 63], pid >>= 6;
- *p++ = tbl[pid & 63], pid >>= 6;
+ {
+ unsigned int pid = (unsigned int) getpid ();
+ *p++ = tbl[(pid >> 0) & 63];
+ *p++ = tbl[(pid >> 6) & 63];
+ *p++ = tbl[(pid >> 12) & 63];
+ }
/* Here we try to minimize useless stat'ing when this function is
invoked many times successively with the same PREFIX. We achieve
- this by initializing count to a random value, and incrementing it
- afterwards. */
- if (!count_initialized_p)
- {
- count = (unsigned)time (NULL);
- /* Dumping temacs with a non-zero count_initialized_p wouldn't
- make much sense. */
- if (NILP (Frunning_temacs_p ()))
- count_initialized_p = 1;
- }
+ this by using a very pseudo-random number generator to generate
+ file names unique to this process, with a very long cycle. */
while (1)
{
struct stat ignored;
- unsigned num = count;
- p[0] = tbl[num & 63], num >>= 6;
- p[1] = tbl[num & 63], num >>= 6;
- p[2] = tbl[num & 63], num >>= 6;
+ p[0] = tbl[(temp_name_rand >> 0) & 63];
+ p[1] = tbl[(temp_name_rand >> 6) & 63];
+ p[2] = tbl[(temp_name_rand >> 12) & 63];
/* Poor man's congruential RN generator. Replace with ++count
for debugging. */
- count += 25229;
- count %= 225307;
+ temp_name_rand += 25229;
+ temp_name_rand %= 225307;
QUIT;
{
return Fsignal (Qfile_error,
list3 (build_translated_string ("Creating directory"),
- build_translated_string ("pathame too long"),
+ build_translated_string ("pathname too long"),
dirname_));
}
strncpy (dir, (char *) XSTRING_DATA (dirname_),
return Qnil;
}
-#ifdef S_IFLNK
DEFUN ("make-symbolic-link", Fmake_symbolic_link, 2, 3,
"FMake symbolic link to file: \nFMake symbolic link to file %s: \np", /*
Make a symbolic link to FILENAME, named LINKNAME. Both args strings.
(filename, linkname, ok_if_already_exists))
{
/* This function can GC. GC checked 1997.06.04. */
+ /* XEmacs change: run handlers even if local machine doesn't have symlinks */
Lisp_Object handler;
struct gcpro gcpro1, gcpro2;
RETURN_UNGCPRO (call4 (handler, Qmake_symbolic_link, filename,
linkname, ok_if_already_exists));
+#ifdef S_IFLNK
if (NILP (ok_if_already_exists)
|| INTP (ok_if_already_exists))
barf_or_query_if_file_exists (linkname, "make it a link",
report_file_error ("Making symbolic link",
list2 (filename, linkname));
}
+#endif /* S_IFLNK */
+
UNGCPRO;
return Qnil;
}
-#endif /* S_IFLNK */
#ifdef HPUX_NET
(filename))
{
/* This function can GC. GC checked 1997.04.10. */
+ /* XEmacs change: run handlers even if local machine doesn't have symlinks */
#ifdef S_IFLNK
char *buf;
int bufsize;
int valsize;
Lisp_Object val;
+#endif
Lisp_Object handler;
struct gcpro gcpro1;
if (!NILP (handler))
return call2 (handler, Qfile_symlink_p, filename);
+#ifdef S_IFLNK
bufsize = 100;
while (1)
{
DEFSUBR (Fdelete_file);
DEFSUBR (Frename_file);
DEFSUBR (Fadd_name_to_file);
-#ifdef S_IFLNK
DEFSUBR (Fmake_symbolic_link);
-#endif /* S_IFLNK */
#ifdef HPUX_NET
DEFSUBR (Fsysnetunam);
#endif /* HPUX_NET */
#ifdef WINDOWSNT
Vdirectory_sep_char = make_char ('\\');
#else
- Vdirectory_sep_char = make_char ('/');
+ Vdirectory_sep_char = make_char ('/');
#endif
+
+ reinit_vars_of_fileio ();
+}
+
+void
+reinit_vars_of_fileio (void)
+{
+ /* We want temp_name_rand to be initialized to a value likely to be
+ unique to the process, not to the executable. The danger is that
+ two different XEmacs processes using the same binary on different
+ machines creating temp files in the same directory will be
+ unlucky enough to have the same pid. If we randomize using
+ process startup time, then in practice they will be unlikely to
+ collide. We use the microseconds field so that scripts that start
+ simultaneous XEmacs processes on multiple machines will have less
+ chance of collision. */
+ {
+ EMACS_TIME thyme;
+
+ EMACS_GET_TIME (thyme);
+ temp_name_rand = (unsigned int) (EMACS_SECS (thyme) ^ EMACS_USECS (thyme));
+ }
}
projects / chise / xemacs-chise.git.1 / blobdiff