1 files changed, 208 insertions, 0 deletions
diff --git a/sysdeps/posix/tempname.c b/sysdeps/posix/tempname.c
new file mode 100644
index 0000000000..f2da66a211
--- /dev/null
+++ b/sysdeps/posix/tempname.c
@@ -0,0 +1,208 @@
+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* Return nonzero if DIR is an existent directory.  */
+static int
+DEFUN(diraccess, (dir), CONST char *dir)
+{
+  struct stat buf;
+  return __stat (dir, &buf) == 0 && S_ISDIR (buf.st_mode);
+}
+
+/* Return nonzero if FILE exists.  */
+static int
+DEFUN(exists, (file), CONST char *file)
+{
+  /* We can stat the file even if we can't read its data.  */
+  struct stat st;
+  int save = errno;
+  if (__stat (file, &st) == 0)
+    return 1;
+  else
+    {
+      /* We report that the file exists if stat failed for a reason other
+	 than nonexistence.  In this case, it may or may not exist, and we
+	 don't know; but reporting that it does exist will never cause any
+	 trouble, while reporting that it doesn't exist when it does would
+	 violate the interface of __stdio_gen_tempname.  */
+      int exists = errno != ENOENT;
+      errno = save;
+      return exists;
+    }
+}
+
+
+/* These are the characters used in temporary filenames.  */
+static CONST char letters[] =
+  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+/* Generate a temporary filename and return it (in a static buffer).  If
+   STREAMPTR is not NULL, open a stream "w+b" on the file and set
+   *STREAMPTR to it.  If DIR_SEARCH is nonzero, DIR and PFX are used as
+   described for tempnam.  If not, a temporary filename in P_tmpdir with no
+   special prefix is generated.  If LENPTR is not NULL, *LENPTR is set the
+   to length (including the terminating '\0') of the resultant filename,
+   which is returned.  This goes through a cyclic pattern of all possible
+   filenames consisting of five decimal digits of the current pid and three
+   of the characters in `letters'.  Data for tempnam and tmpnam is kept
+   separate, but when tempnam is using P_tmpdir and no prefix (i.e, it is
+   identical to tmpnam), the same data is used.  Each potential filename is
+   tested for an already-existing file of the same name, and no name of an
+   existing file will be returned.  When the cycle reaches its end
+   (12345ZZZ), NULL is returned.  */
+char *
+DEFUN(__stdio_gen_tempname, (dir, pfx, dir_search, lenptr, streamptr),
+      CONST char *dir AND CONST char *pfx AND
+      int dir_search AND size_t *lenptr AND
+      FILE **streamptr)
+{
+  int saverrno = errno;
+  static CONST char tmpdir[] = P_tmpdir;
+  static size_t indices[2];
+  size_t *idx;
+  static char buf[FILENAME_MAX];
+  static pid_t oldpid = (pid_t) 0;
+  pid_t pid = __getpid();
+  register size_t len, plen, dlen;
+
+  if (dir_search)
+    {
+      register CONST char *d = getenv ("TMPDIR");
+      if (d != NULL && !diraccess (d))
+	d = NULL;
+      if (d == NULL && dir != NULL && diraccess (dir))
+	d = dir;
+      if (d == NULL && diraccess (tmpdir))
+	d = tmpdir;
+      if (d == NULL && diraccess ("/tmp"))
+	d = "/tmp";
+      if (d == NULL)
+	{
+	  errno = ENOENT;
+	  return NULL;
+	}
+      dir = d;
+    }
+  else
+    dir = tmpdir;
+
+  dlen = strlen (dir);
+
+ /* Remove trailing slashes from the directory name.  */
+  while (dlen > 1 && dir[dlen - 1] == '/')
+    --dlen;
+
+  if (pfx != NULL && *pfx != '\0')
+    {
+      plen = strlen (pfx);
+      if (plen > 5)
+	plen = 5;
+    }
+  else
+    plen = 0;
+
+  if (dir != tmpdir && !strcmp (dir, tmpdir))
+    dir = tmpdir;
+  idx = &indices[(plen == 0 && dir == tmpdir) ? 1 : 0];
+
+  if (pid != oldpid)
+    {
+      oldpid = pid;
+      indices[0] = indices[1] = 0;
+    }
+
+  len = dlen + 1 + plen + 5 + 3;
+  while (*idx < ((sizeof (letters) - 1) * (sizeof (letters) - 1) *
+		 (sizeof (letters) - 1)))
+    {
+      const size_t i = (*idx)++;
+
+      /* Construct a file name and see if it already exists.
+
+	 We use a single counter in *IDX to cycle each of three
+	 character positions through each of 62 possible letters.  */
+
+      if (sizeof (buf) < len ||
+	  sprintf (buf, "%.*s/%.*s%.5d%c%c%c",
+		   (int) dlen, dir, (int) plen,
+		   pfx, pid % 100000,
+		   letters[i % (sizeof (letters) - 1)],
+		   letters[(i / (sizeof (letters) - 1))
+			   % (sizeof (letters) - 1)],
+		   letters[(i / ((sizeof (letters) - 1) *
+				 (sizeof (letters) - 1)))
+			   % (sizeof (letters) - 1)]
+		   ) != (int) len)
+	return NULL;
+
+      if (streamptr != NULL)
+	{
+	  /* Try to create the file atomically.  */
+	  int fd = __open (buf, O_RDWR|O_CREAT|O_EXCL, 0666);
+	  if (fd >= 0)
+	    {
+	      /* We got a new file that did not previously exist.
+		 Create a stream for it.  */
+	      *streamptr = __newstream ();
+	      if (*streamptr == NULL)
+		{
+		  /* We lost trying to create a stream (out of memory?).
+		     Nothing to do but remove the file, close the descriptor,
+		     and return failure.  */
+		  const int save = errno;
+		  (void) remove (buf);
+		  (void) __close (fd);
+		  errno = save;
+		  return NULL;
+		}
+	      (*streamptr)->__cookie = (PTR) (long int) fd;
+	      (*streamptr)->__mode.__write = 1;
+	      (*streamptr)->__mode.__read = 1;
+	      (*streamptr)->__mode.__binary = 1;
+	    }
+	  else
+	    continue;
+	}
+      else if (exists (buf))
+	continue;
+
+      /* If the file already existed we have continued the loop above,
+	 so we only get here when we have a winning name to return.  */
+
+      errno = saverrno;
+
+      if (lenptr != NULL)
+	*lenptr = len + 1;
+      return buf;
+    }
+
+  /* We got out of the loop because we ran out of combinations to try.  */
+  errno = EEXIST;		/* ? */
+  return NULL;
+}