os.c

apache简化版

/* ====================================================================
 * Copyright (c) 1998 The Apache Group.  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. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED 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 APACHE GROUP OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

/*
 * This file will include OS specific functions which are not inlineable.
 * Any inlineable functions should be defined in os-inline.c instead.
 */

#include "httpd.h"
#include "http_core.h"
#include "os.h"

/* Check the Content-Type to decide if conversion is needed */
int ap_checkconv(struct request_rec *r)
{
    int convert_to_ascii;
    const char *type;

    /* To make serving of "raw ASCII text" files easy (they serve faster 
     * since they don't have to be converted from EBCDIC), a new
     * "magic" type prefix was invented: text/x-ascii-{plain,html,...}
     * If we detect one of these content types here, we simply correct
     * the type to the real text/{plain,html,...} type. Otherwise, we
     * set a flag that translation is required later on.
     */

    type = (r->content_type == NULL) ? ap_default_type(r) : r->content_type;

    /* If no content type is set then treat it as (ebcdic) text/plain */
    convert_to_ascii = (type == NULL);

    /* Conversion is applied to text/ files only, if ever. */
    if (type && (strncasecmp(type, "text/", 5) == 0 ||
		 strncasecmp(type, "message/", 8) == 0)) {
	if (strncasecmp(type, ASCIITEXT_MAGIC_TYPE_PREFIX,
			sizeof(ASCIITEXT_MAGIC_TYPE_PREFIX)-1) == 0)
	    r->content_type = ap_pstrcat(r->pool, "text/",
					 type+sizeof(ASCIITEXT_MAGIC_TYPE_PREFIX)-1,
					 NULL);
        else
	    /* translate EBCDIC to ASCII */
	    convert_to_ascii = 1;
    }
    /* Enable conversion if it's a text document */
    ap_bsetflag(r->connection->client, B_EBCDIC2ASCII, convert_to_ascii);

    return convert_to_ascii;
}