/*
* 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.
*/
/* 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.
*/
/*
FUNCTION
<<mktemp>>, <<mkstemp>>, <<mkostemp>>, <<mkstemps>>,
<<mkostemps>>---generate unused file name
<<mkdtemp>>---generate unused directory
INDEX
mktemp
INDEX
mkdtemp
INDEX
mkstemp
INDEX
mkstemps
INDEX
mkostemp
INDEX
mkostemps
INDEX
_mktemp_r
INDEX
_mkdtemp_r
INDEX
_mkstemp_r
INDEX
_mkstemps_r
INDEX
_mkostemp_r
INDEX
_mkostemps_r
ANSI_SYNOPSIS
#include <stdlib.h>
char *mktemp(char *<[path]>);
char *mkdtemp(char *<[path]>);
int mkstemp(char *<[path]>);
int mkstemps(char *<[path]>, int <[suffixlen]>);
int mkostemp(char *<[path]>, int <[flags]>);
int mkostemps(char *<[path]>, int <[suffixlen]>, int <[flags]>);
char *_mktemp_r(struct _reent *<[reent]>, char *<[path]>);
char *_mkdtemp_r(struct _reent *<[reent]>, char *<[path]>);
int *_mkstemp_r(struct _reent *<[reent]>, char *<[path]>);
int *_mkstemps_r(struct _reent *<[reent]>, char *<[path]>, int <[len]>);
int *_mkostemp_r(struct _reent *<[reent]>, char *<[path]>,
int <[flags]>);
int *_mkostemps_r(struct _reent *<[reent]>, char *<[path]>, int <[len]>,
int <[flags]>);
DESCRIPTION
<<mktemp>>, <<mkstemp>>, and <<mkstemps>> attempt to generate a file name
that is not yet in use for any existing file. <<mkstemp>> and <<mkstemps>>
create the file and open it for reading and writing; <<mktemp>> simply
generates the file name (making <<mktemp>> a security risk). <<mkostemp>>
and <<mkostemps>> allow the addition of other <<open>> flags, such
as <<O_CLOEXEC>>, <<O_APPEND>>, or <<O_SYNC>>. On platforms with a
separate text mode, <<mkstemp>> forces <<O_BINARY>>, while <<mkostemp>>
allows the choice between <<O_BINARY>>, <<O_TEXT>>, or 0 for default.
<<mkdtemp>> attempts to create a directory instead of a file, with a
permissions mask of 0700.
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 at least six `<<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. With <<mkstemps>>, the `<<X>>'
characters end <[suffixlen]> bytes before the end of the string.
The alternate functions <<_mktemp_r>>, <<_mkdtemp_r>>, <<_mkstemp_r>>,
<<_mkostemp_r>>, <<_mkostemps_r>>, and <<_mkstemps_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>>. Be aware that there is an inherent race between
generating the name and attempting to create a file by that name;
you are advised to use <<O_EXCL|O_CREAT>>.
<<mkdtemp>> returns the pointer <[path]> to the modified string if the
directory was created, otherwise it returns <<NULL>>.
<<mkstemp>>, <<mkstemps>>, <<mkostemp>>, and <<mkostemps>> return 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>>.
NOTES
Never use <<mktemp>>. The generated filenames are easy to guess and
there's a race between the test if the file exists and the creation
of the file. In combination this makes <<mktemp>> prone to attacks
and using it is a security risk. Whenever possible use <<mkstemp>>
instead. It doesn't suffer the race condition.
PORTABILITY
ANSI C does not require either <<mktemp>> or <<mkstemp>>; the System
V Interface Definition requires <<mktemp>> as of Issue 2. POSIX 2001
requires <<mkstemp>>, and POSIX 2008 requires <<mkdtemp>> while
deprecating <<mktemp>>. <<mkstemps>>, <<mkostemp>>, and <<mkostemps>>
are not standardized.
Supporting OS subroutines required: <<getpid>>, <<mkdir>>, <<open>>, <<stat>>.
*/
#include <_ansi.h>
#include <stdlib.h>
#include <reent.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
static int
_DEFUN(_gettemp, (ptr, path, doopen, domkdir, suffixlen, flags),
struct _reent *ptr _AND
char *path _AND
register int *doopen _AND
int domkdir _AND
size_t suffixlen _AND
int flags)
{
register char *start, *trv;
char *end;
#ifdef __USE_INTERNAL_STAT64
struct stat64 sbuf;
#else
struct stat sbuf;
#endif
unsigned int pid;
pid = _getpid_r (ptr);
for (trv = path; *trv; ++trv) /* extra X's get set to 0's */
continue;
if (trv - path < suffixlen)
{
ptr->_errno = EINVAL;
return 0;
}
trv -= suffixlen;
end = trv;
while (path < trv && *--trv == 'X')
{
*trv = (pid % 10) + '0';
pid /= 10;
}
if (end - trv < 6)
{
ptr->_errno = EINVAL;
return 0;
}
/*
* 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';
#ifdef __USE_INTERNAL_STAT64
if (_stat64_r (ptr, path, &sbuf))
#else
if (_stat_r (ptr, path, &sbuf))
#endif
return (0);
if (!(sbuf.st_mode & S_IFDIR))
{
ptr->_errno = ENOTDIR;
return (0);
}
*trv = '/';
break;
}
}
for (;;)
{
#if !defined _ELIX_LEVEL || _ELIX_LEVEL >= 4
if (domkdir)
{
#ifdef HAVE_MKDIR
if (_mkdir_r (ptr, path, 0700) == 0)
return 1;
if (ptr->_errno != EEXIST)
return 0;
#else /* !HAVE_MKDIR */
ptr->_errno = ENOSYS;
return 0;
#endif /* !HAVE_MKDIR */
}
else
#endif /* _ELIX_LEVEL */
if (doopen)
{
if ((*doopen = _open_r (ptr, path, O_CREAT | O_EXCL | O_RDWR | flags,
0600)) >= 0)
return 1;
if (ptr->_errno != EEXIST)
return 0;
}
#ifdef __USE_INTERNAL_STAT64
else if (_stat64_r (ptr, path, &sbuf))
#else
else if (_stat_r (ptr, path, &sbuf))
#endif
return (ptr->_errno == ENOENT ? 1 : 0);
/* tricky little algorithm for backward compatibility */
for (trv = start;;)
{
if (trv == end)
return 0;
if (*trv == 'z')
*trv++ = 'a';
else
{
/* Safe, since it only encounters 7-bit characters. */
if (isdigit ((unsigned char) *trv
)) *trv = 'a';
else
++ * trv;
break;
}
}
}
/*NOTREACHED*/
}
#ifndef O_BINARY
# define O_BINARY 0
#endif
int
_DEFUN(_mkstemp_r, (ptr, path),
struct _reent *ptr _AND
char *path)
{
int fd;
return (_gettemp (ptr, path, &fd, 0, 0, O_BINARY) ? fd : -1);
}
#if !defined _ELIX_LEVEL || _ELIX_LEVEL >= 4
char *
_DEFUN(_mkdtemp_r, (ptr, path),
struct _reent *ptr _AND
char *path)
{
return (_gettemp (ptr, path, (int *) NULL, 1, 0, 0) ? path : NULL);
}
int
_DEFUN(_mkstemps_r, (ptr, path, len),
struct _reent *ptr _AND
char *path _AND
int len)
{
int fd;
return (_gettemp (ptr, path, &fd, 0, len, O_BINARY) ? fd : -1);
}
int
_DEFUN(_mkostemp_r, (ptr, path, flags),
struct _reent *ptr _AND
char *path _AND
int flags)
{
int fd;
return (_gettemp (ptr, path, &fd, 0, 0, flags & ~O_ACCMODE) ? fd : -1);
}
int
_DEFUN(_mkostemps_r, (ptr, path, len, flags),
struct _reent *ptr _AND
char *path _AND
int len _AND
int flags)
{
int fd;
return (_gettemp (ptr, path, &fd, 0, len, flags & ~O_ACCMODE) ? fd : -1);
}
#endif /* _ELIX_LEVEL */
char *
_DEFUN(_mktemp_r, (ptr, path),
struct _reent *ptr _AND
char *path)
{
return (_gettemp (ptr, path, (int *) NULL, 0, 0, 0) ? path : (char *) NULL);
}
#ifndef _REENT_ONLY
int
_DEFUN(mkstemp, (path),
char *path)
{
int fd;
return (_gettemp (_REENT, path, &fd, 0, 0, O_BINARY) ? fd : -1);
}
# if !defined _ELIX_LEVEL || _ELIX_LEVEL >= 4
char *
_DEFUN(mkdtemp, (path),
char *path)
{
return (_gettemp (_REENT, path, (int *) NULL, 1, 0, 0) ? path : NULL);
}
int
_DEFUN(mkstemps, (path, len),
char *path _AND
int len)
{
int fd;
return (_gettemp (_REENT, path, &fd, 0, len, O_BINARY) ? fd : -1);
}
int
_DEFUN(mkostemp, (path, flags),
char *path _AND
int flags)
{
int fd;
return (_gettemp (_REENT, path, &fd, 0, 0, flags & ~O_ACCMODE) ? fd : -1);
}
int
_DEFUN(mkostemps, (path, len, flags),
char *path _AND
int len _AND
int flags)
{
int fd;
return (_gettemp (_REENT, path, &fd, 0, len, flags & ~O_ACCMODE) ? fd : -1);
}
# endif /* _ELIX_LEVEL */
char *
_DEFUN(mktemp, (path),
char *path)
{
return (_gettemp (_REENT, path, (int *) NULL, 0, 0, 0) ? path : (char *) NULL);
}
#endif /* ! defined (_REENT_ONLY) */