StdLib/LibC/Stdio/gettemp.c

/** @file
  Internal function to generate temporary file name for tmpnam.

  Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials are licensed and made available
  under the terms and conditions of the BSD License that accompanies this
  distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

  Copyright (c) 1987, 1993
   The Regents of the University of California.  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the University nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  SUCH DAMAGE.

  mktemp.c  8.1 (Berkeley) 6/4/93
  NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp
**/
#include  <LibConfig.h>

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#if !defined(HAVE_NBTOOL_CONFIG_H) || !defined(HAVE_MKSTEMP) || !defined(HAVE_MKDTEMP)

#include <sys/EfiCdefs.h>

#include <sys/types.h>
#include <sys/stat.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include  <unistd.h>

#if HAVE_NBTOOL_CONFIG_H
#define GETTEMP   gettemp
#else
#include "reentrant.h"
#include "local.h"
#define GETTEMP   __gettemp
#endif

int
GETTEMP(
  char *path,
  int *doopen,
  int domkdir
  )
{
  char *start, *trv;
  struct stat sbuf;

  /* To guarantee multiple calls generate unique names even if
     the file is not created. 676 different possibilities with 7
     or more X's, 26 with 6 or less. */
  static char xtra[] = "aa";
  int xcnt = 0;

  _DIAGASSERT(path != NULL);
  /* doopen may be NULL */

  /* Move to end of path and count trailing X's. */
  for (trv = path; *trv; ++trv) {
    if (*trv == 'X') {
      xcnt++;
    }
    else {
      xcnt = 0;
    }
  }

  /* Use at least one from xtra.  Use 2 if more than 6 X's. */
  if (*(trv - 1) == 'X')
    *--trv = xtra[0];
  if (xcnt > 6 && *(trv - 1) == 'X')
    *--trv = xtra[1];

  /* Set remaining X's to 0's. */
  while (*--trv == 'X') {
    *trv = '0';
  }

  /* update xtra for next call. */
  if (xtra[0] != 'z')
    xtra[0]++;
  else {
    xtra[0] = 'a';
    if (xtra[1] != 'z')
      xtra[1]++;
    else
      xtra[1] = 'a';
  }

  /*
   * check the target directory; if you have six X's and it
   * doesn't exist this runs for a *very* long time.
   */
  for (start = trv + 1;; --trv) {
    if (trv <= path)
      break;
    if (*trv == '/') {
      *trv = '\0';
      if (stat(path, &sbuf))
        return (0);
      if (!S_ISDIR(sbuf.st_mode)) {
        errno = ENOTDIR;
        return (0);
      }
      *trv = '/';
      break;
    }
  }

  for (;;) {
    if (doopen) {
      if ((*doopen =
          open(path, O_CREAT | O_EXCL | O_RDWR, 0600)) >= 0)
        return (1);
      if (errno != EEXIST)
        return (0);
    } else if (domkdir) {
      if (mkdir(path, 0700) >= 0)
        return (1);
      if (errno != EEXIST)
        return (0);
    } else if (lstat(path, &sbuf))
      return (errno == ENOENT ? 1 : 0);

    /* tricky little algorithm for backward compatibility */
    for (trv = start;;) {
      if (!*trv)
        return (0);
      if (*trv == 'z') {
        *trv++ = 'a';
      }
      else {
        if (isdigit((unsigned char)*trv))
          *trv = 'a';
        else
          ++*trv;
        break;
      }
    }
  }
  /*NOTREACHED*/
}

#endif /* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */