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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) */
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