mktemp.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 108 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  Implementation of _mktemp().
*
****************************************************************************/


#include "variety.h"
#include "widechar.h"
#include <io.h>
#include <malloc.h>
#include <mbstring.h>
#include <process.h>
#include <stdio.h>
#include <string.h>
#ifdef __NT__
    #include <windows.h>
#endif


static int is_valid_template( CHAR_TYPE *template, CHAR_TYPE **xs )
{
    int                 len;
    CHAR_TYPE           *p;

    /*** Ensure the last 6 characters form the string "XXXXXX" ***/
    len = __F_NAME(_mbslen,wcslen)( template );
    if( len < 6 ) {
        return( 0 );        /* need room for "XXXXXX" */
    }
#ifdef __WIDECHAR__
    p = template + len - 6;
    if( wcscmp( p, L"XXXXXX" ) ) {
        return( 0 );
    }
#else
    p = _mbsninc( template, len - 6 );
    if( _mbscmp( p, "XXXXXX" ) ) {
        return( 0 );
    }
#endif
    *xs = p;

    return( 1 );
}


_WCRTLINK CHAR_TYPE *__F_NAME(_mktemp,_wmktemp)( CHAR_TYPE *template )
{
    CHAR_TYPE           letter;
    unsigned            pid;
    CHAR_TYPE           *xs;

    /*** Ensure the template is valid ***/
    if( !is_valid_template( template, &xs ) ) {
        return( NULL );
    }

    /*** Get the process/thread ID ***/
#ifdef __NT__
    #ifdef __SW_BM
        pid = GetCurrentThreadId();     /* thread ID for multi-thread */
    #else
        pid = GetCurrentProcessId();    /* process ID for single-thread */
    #endif
#else
    pid = getpid();
#endif
    pid %= 100000;      /* first few digits tend to be repeated under 95 */

    /*** Try to build a unique filename ***/
    for( letter = 'a'; letter <= 'z'; letter++ ) {
#ifdef __WIDECHAR__
        _bwprintf( xs, wcslen( xs ) + 1, L"%c%05u", letter, pid );
#else
        _bprintf( xs, strlen( xs ) + 1, "%c%05u", letter, pid );
#endif
        if( __F_NAME(access,_waccess)( template, F_OK ) != 0 ) {
            return( template );
        }
    }
    return( NULL );
}