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/* This is file MKTEMP.C */

/* This file may have been modified by DJ Delorie (Jan 1991).  If so,

** these modifications are Copyright (C) 1991 DJ Delorie

*/

/*

 * Copyright (c) 1987 Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms are permitted

 * provided that: (1) source distributions retain this entire copyright

 * notice and comment, and (2) distributions including binaries display

 * the following acknowledgement:  ``This product includes software

 * developed by the University of California, Berkeley and its contributors''

 * in the documentation or other materials provided with the distribution

 * and in all advertising materials mentioning features or use of this

 * software. 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

/*

FUNCTION

<<mktemp>>, <<mkstemp>>---generate unused file name

INDEX

        mktemp

INDEX

        mkstemp

INDEX

        _mktemp_r

INDEX

        _mkstemp_r

ANSI_SYNOPSIS

        #include <stdio.h>

        char *mktemp(char *<[path]>);

        int mkstemp(char *<[path]>);

        char *_mktemp_r(void *<[reent]>, char *<[path]>);

        int *_mkstemp_r(void *<[reent]>, char *<[path]>);

TRAD_SYNOPSIS

        #include <stdio.h>

        char *mktemp(<[path]>)

        char *<[path]>;

        int mkstemp(<[path]>)

        char *<[path]>;

        char *_mktemp_r(<[reent]>, <[path]>)

        char *<[reent]>;

        char *<[path]>;

        int _mkstemp_r(<[reent]>, <[path]>)

        char *<[reent]>;

        char *<[path]>;

DESCRIPTION

<<mktemp>> and <<mkstemp>> attempt to generate a file name that is not

yet in use for any existing file.  <<mkstemp>> creates the file and

opens it for reading and writing; <<mktemp>> simply generates the file name.

You supply a simple pattern for the generated file name, as the string

at <[path]>.  The pattern should be a valid filename (including path

information if you wish) ending with some number of `<<X>>'

characters.  The generated filename will match the leading part of the

name you supply, with the trailing `<<X>>' characters replaced by some

combination of digits and letters.

The alternate functions <<_mktemp_r>> and <<_mkstemp_r>> are reentrant

versions.  The extra argument <[reent]> is a pointer to a reentrancy

structure.

RETURNS

<<mktemp>> returns the pointer <[path]> to the modified string

representing an unused filename, unless it could not generate one, or

the pattern you provided is not suitable for a filename; in that case,

it returns <<NULL>>.

<<mkstemp>> returns a file descriptor to the newly created file,

unless it could not generate an unused filename, or the pattern you

provided is not suitable for a filename; in that case, it returns

<<-1>>.

PORTABILITY

ANSI C does not require either <<mktemp>> or <<mkstemp>>; the System

V Interface Definition requires <<mktemp>> as of Issue 2.

Supporting OS subroutines required: <<getpid>>, <<open>>, <<stat>>.

*/

#include <sys/types.h>

#include <fcntl.h>

#include <sys/stat.h>

#include <errno.h>

#include <stdio.h>

#include <ctype.h>

#include <reent.h>

static int

_DEFUN (_gettemp, (ptr, path, doopen),

        struct _reent *ptr _AND

        char *path _AND

        register int *doopen)

{

  register char *start, *trv;

  struct stat sbuf;

  unsigned int pid;

  pid = _getpid_r (ptr);

  for (trv = path; *trv; ++trv)         /* extra X's get set to 0's */

    continue;

  while (*--trv == 'X')

    {

      *trv = (pid % 10) + '0';

      pid /= 10;

    }

  /*

   * 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_r (ptr, path, &sbuf))

            return (0);

          if (!(sbuf.st_mode & S_IFDIR))

            {

              ptr->_errno = ENOTDIR;

              return (0);

            }

          *trv = '/';

          break;

        }

    }

  for (;;)

    {

      if (doopen)

        {

          if ((*doopen = _open_r (ptr, path, O_CREAT | O_EXCL | O_RDWR, 0600))

              >= 0)

            return 1;

#if defined(__CYGWIN32__) || defined(__CYGWIN__)

          if (ptr->_errno != EEXIST && ptr->_errno != EACCES)

#else

          if (ptr->_errno != EEXIST)

#endif

            return 0;

        }

      else if (_stat_r (ptr, path, &sbuf))

        return (ptr->_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 (*trv))

                *trv = 'a';

              else

                ++ * trv;

              break;

            }

        }

    }

  /*NOTREACHED*/

}

int

_DEFUN (_mkstemp_r, (ptr, path),

        struct _reent *ptr _AND

        char *path)

{

  int fd;

  return (_gettemp (ptr, path, &fd) ? fd : -1);

}

char *

_DEFUN (_mktemp_r, (ptr, path),

        struct _reent *ptr _AND

        char *path)

{

  return (_gettemp (ptr, path, (int *) NULL) ? path : (char *) NULL);

}

#ifndef _REENT_ONLY

int

_DEFUN (mkstemp, (path),

        char *path)

{

  int fd;

  return (_gettemp (_REENT, path, &fd) ? fd : -1);

}

char *

_DEFUN (mktemp, (path),

        char *path)

{

  return (_gettemp (_REENT, path, (int *) NULL) ? path : (char *) NULL);

}

#endif /* ! defined (_REENT_ONLY) */