Add stuff from gnulib.

gl/mkdtemp.c

@@ -0,0 +1,203 @@
+/* Copyright (C) 1999, 2001-2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Extracted from misc/mkdtemp.c and sysdeps/posix/tempname.c.  */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+/* Specification.  */
+#include "mkdtemp.h"
+
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <stdio.h>
+#ifndef TMP_MAX
+# define TMP_MAX 238328
+#endif
+
+#if HAVE_STDINT_H || _LIBC
+# include <stdint.h>
+#endif
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+
+#if HAVE_UNISTD_H || _LIBC
+# include <unistd.h>
+#endif
+
+#if HAVE_GETTIMEOFDAY || _LIBC
+# if HAVE_SYS_TIME_H || _LIBC
+#  include <sys/time.h>
+# endif
+#else
+# if HAVE_TIME_H || _LIBC
+#  include <time.h>
+# endif
+#endif
+
+#include <sys/stat.h>
+#if STAT_MACROS_BROKEN
+# undef S_ISDIR
+#endif
+#if !defined S_ISDIR && defined S_IFDIR
+# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
+#endif
+#if !S_IRUSR && S_IREAD
+# define S_IRUSR S_IREAD
+#endif
+#if !S_IRUSR
+# define S_IRUSR 00400
+#endif
+#if !S_IWUSR && S_IWRITE
+# define S_IWUSR S_IWRITE
+#endif
+#if !S_IWUSR
+# define S_IWUSR 00200
+#endif
+#if !S_IXUSR && S_IEXEC
+# define S_IXUSR S_IEXEC
+#endif
+#if !S_IXUSR
+# define S_IXUSR 00100
+#endif
+
+#ifdef __MINGW32__
+/* mingw's mkdir() function has 1 argument, but we pass 2 arguments.
+   Therefore we have to disable the argument count checking.  */
+# define mkdir ((int (*)()) mkdir)
+#endif
+
+#if !_LIBC
+# define __getpid getpid
+# define __gettimeofday gettimeofday
+# define __mkdir mkdir
+#endif
+
+/* Use the widest available unsigned type if uint64_t is not
+   available.  The algorithm below extracts a number less than 62**6
+   (approximately 2**35.725) from uint64_t, so ancient hosts where
+   uintmax_t is only 32 bits lose about 3.725 bits of randomness,
+   which is better than not having mkstemp at all.  */
+#if !defined UINT64_MAX && !defined uint64_t
+# define uint64_t uintmax_t
+#endif
+
+/* These are the characters used in temporary filenames.  */
+static const char letters[] =
+"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+/* Generate a temporary file name based on TMPL.  TMPL must match the
+   rules for mk[s]temp (i.e. end in "XXXXXX").  The name constructed
+   does not exist at the time of the call to __gen_tempname.  TMPL is
+   overwritten with the result.
+
+   KIND is:
+   __GT_DIR:		create a directory, which will be mode 0700.
+
+   We use a clever algorithm to get hard-to-predict names. */
+static int
+gen_tempname (char *tmpl)
+{
+  int len;
+  char *XXXXXX;
+  static uint64_t value;
+  uint64_t random_time_bits;
+  int count, fd = -1;
+  int save_errno = errno;
+
+  len = strlen (tmpl);
+  if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  /* This is where the Xs start.  */
+  XXXXXX = &tmpl[len - 6];
+
+  /* Get some more or less random data.  */
+#ifdef RANDOM_BITS
+  RANDOM_BITS (random_time_bits);
+#else
+# if HAVE_GETTIMEOFDAY || _LIBC
+  {
+    struct timeval tv;
+    __gettimeofday (&tv, NULL);
+    random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
+  }
+# else
+  random_time_bits = time (NULL);
+# endif
+#endif
+  value += random_time_bits ^ __getpid ();
+
+  for (count = 0; count < TMP_MAX; value += 7777, ++count)
+    {
+      uint64_t v = value;
+
+      /* Fill in the random bits.  */
+      XXXXXX[0] = letters[v % 62];
+      v /= 62;
+      XXXXXX[1] = letters[v % 62];
+      v /= 62;
+      XXXXXX[2] = letters[v % 62];
+      v /= 62;
+      XXXXXX[3] = letters[v % 62];
+      v /= 62;
+      XXXXXX[4] = letters[v % 62];
+      v /= 62;
+      XXXXXX[5] = letters[v % 62];
+
+      fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
+
+      if (fd >= 0)
+	{
+	  __set_errno (save_errno);
+	  return fd;
+	}
+      else if (errno != EEXIST)
+	return -1;
+    }
+
+  /* We got out of the loop because we ran out of combinations to try.  */
+  __set_errno (EEXIST);
+  return -1;
+}
+
+/* Generate a unique temporary directory from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the filename unique.
+   The directory is created, mode 700, and its name is returned.
+   (This function comes from OpenBSD.) */
+char *
+mkdtemp (char *template)
+{
+  if (gen_tempname (template))
+    return NULL;
+  else
+    return template;
+}