displayobject.c

harvest是一个下载html网页得机器人

static char rcsid[] = "$Id: DisplayObject.c,v 2.5 1997/12/12 16:02:09 sxw Exp $";
/*
 *  DisplayObject.c - httpd-based CGI program that HTML-ifies a
 *  SOIF Object for clients.
 *
 *  Usage:  Run from cgi-bin directory under httpd server
 *
 *  Supports	'object'	name of URL data relative to CGI server
 *		'attribute'	return data associated with the attribute only
 *		'type'		MIME data type for attribute data
 *
 *  Darren Hardy, University of Colorado - Boulder, July 1994
 *
 *
 *  DEBUG: none
 *  AUTHOR: Harvest derived
 *
 *  Harvest Indexer http://harvest.sourceforge.net/
 *  -----------------------------------------------
 *
 *  The Harvest Indexer is a continued development of code developed by
 *  the Harvest Project. Development is carried out by numerous individuals
 *  in the Internet community, and is not officially connected with the
 *  original Harvest Project or its funding sources.
 *
 *  Please mail [e-mail] if you are interested in participating
 *  in the development effort.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*  ----------------------------------------------------------------------
 *  Copyright (c) 1994, 1995.  All rights reserved.
 *
 *    The Harvest software was developed by the Internet Research Task
 *    Force Research Group on Resource Discovery (IRTF-RD):
 *
 *          Mic Bowman of Transarc Corporation.
 *          Peter Danzig of the University of Southern California.
 *          Darren R. Hardy of the University of Colorado at Boulder.
 *          Udi Manber of the University of Arizona.
 *          Michael F. Schwartz of the University of Colorado at Boulder.
 *          Duane Wessels of the University of Colorado at Boulder.
 *
 *    This copyright notice applies to software in the Harvest
 *    ``src/'' directory only.  Users should consult the individual
 *    copyright notices in the ``components/'' subdirectories for
 *    copyright information about other software bundled with the
 *    Harvest source code distribution.
 *
 *  TERMS OF USE
 *
 *    The Harvest software may be used and re-distributed without
 *    charge, provided that the software origin and research team are
 *    cited in any use of the system.  Most commonly this is
 *    accomplished by including a link to the Harvest Home Page
 *    (http://harvest.cs.colorado.edu/) from the query page of any
 *    Broker you deploy, as well as in the query result pages.  These
 *    links are generated automatically by the standard Broker
 *    software distribution.
 *
 *    The Harvest software is provided ``as is'', without express or
 *    implied warranty, and with no support nor obligation to assist
 *    in its use, correction, modification or enhancement.  We assume
 *    no liability with respect to the infringement of copyrights,
 *    trade secrets, or any patents, and are not responsible for
 *    consequential damages.  Proper use of the Harvest software is
 *    entirely the responsibility of the user.
 *
 *  DERIVATIVE WORKS
 *
 *    Users may make derivative works from the Harvest software, subject
 *    to the following constraints:
 *
 *      - You must include the above copyright notice and these
 *        accompanying paragraphs in all forms of derivative works,
 *        and any documentation and other materials related to such
 *        distribution and use acknowledge that the software was
 *        developed at the above institutions.
 *
 *      - You must notify IRTF-RD regarding your distribution of
 *        the derivative work.
 *
 *      - You must clearly notify users that your are distributing
 *        a modified version and not the original Harvest software.
 *
 *      - Any derivative product is also subject to these copyright
 *        and use restrictions.
 *
 *    Note that the Harvest software is NOT in the public domain.  We
 *    retain copyright, as specified above.
 *
 *  HISTORY OF FREE SOFTWARE STATUS
 *
 *    Originally we required sites to license the software in cases
 *    where they were going to build commercial products/services
 *    around Harvest.  In June 1995 we changed this policy.  We now
 *    allow people to use the core Harvest software (the code found in
 *    the Harvest ``src/'' directory) for free.  We made this change
 *    in the interest of encouraging the widest possible deployment of
 *    the technology.  The Harvest software is really a reference
 *    implementation of a set of protocols and formats, some of which
 *    we intend to standardize.  We encourage commercial
 *    re-implementations of code complying to this set of standards.
 *
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <memory.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/stat.h>
#include "util.h"
#include "url.h"
#include "template.h"
#include "autoconf.h"

/*
 *  USE_DIRECTORY_LISTING - For Directory-Listing Broker support
 */
#ifndef USE_DIRECTORY_LISTING
#define USE_DIRECTORY_LISTING
#endif

/* from util.c */
void getword(), unescape_url(), plustospace(), nltospace();
char x2c();
void *xmalloc ();

/* Local functions */
void do_shutdown();
char *get_time();
static void htmlify_file();

#define LF 10

#define ENTSIZ 64
typedef struct {
	char *name;
	char *val;
} entry;
entry *entries;
char *errmsg;
char *tfile = NULL;
char *select_attribute = NULL;
char *data_type = NULL;
int wrote_http_header = 0;

#ifdef USE_DIRECTORY_LISTING
static void do_directory_listing();
#endif


/*
 *  fatal_http() - Print error message to user via stdout; and nicely log
 *  the error to stderr where httpd will save it in error_log.
 */
void fatal_http(s)
char *s;
{
	if (!wrote_http_header)
		printf("Content-type: text/html\r\n");
	fprintf(stdout, "\r\n%s\n", s);
	fflush(stdout);
#ifdef DO_STDERR_LOGGING
	fprintf(stderr, "[%s] DisplayObject: %s", get_time(), s);
	fflush(stderr);
#endif
	do_shutdown(1);
}

void do_shutdown(sig)
int sig;
{
	if (tfile != NULL)
		(void)unlink(tfile);
	_exit(sig);
}


/* get_time from NCSA httpd */
char *get_time()
{
	time_t t;
	char *time_string;

	t = time(NULL);
	time_string = ctime(&t);
	time_string[strlen(time_string) - 1] = '\0';
	return (time_string);
}

int main(argc, argv)
int argc;
char *argv[];
{
	int x, m = 0;
	char *cl = getenv("QUERY_STRING");
	char *gl = getenv("REQUEST_METHOD");
	char *sh = getenv("SERVER_NAME");
	char *sp = getenv("SERVER_PORT");
	char *object = (char *) xmalloc (BUFSIZ);/* Holds the object pathname */
	char *objurl = (char *) xmalloc (BUFSIZ);
	URL *up = NULL;
	extern int use_local_cache;

	/* set up signal handlers */
	(void) signal(SIGHUP, do_shutdown);
	(void) signal(SIGINT, do_shutdown);
	(void) signal(SIGQUIT, do_shutdown);
	(void) signal(SIGTERM, do_shutdown);
	(void) signal(SIGALRM, do_shutdown);

	/* init data structures */
	errmsg = (char *) xmalloc (BUFSIZ);
	entries = (entry *) xmalloc (ENTSIZ * sizeof (entry));
	for (x=0; x<ENTSIZ; x++) {
		entries[x].name = (char *) xmalloc (BUFSIZ);
		entries[x].val	= (char *) xmalloc (BUFSIZ);
	}

	/* validity checks */
	if (!gl || (memcmp(gl, "GET", 3))) {
		fatal_http("Reference with a METHOD of GET.");
	} else if (cl == NULL) {
		fatal_http("No query information to decode.");
	} else if (sp == NULL || sh == NULL) {
		fatal_http("Invalid CGI interface! No SERVER_NAME/SERVER_PORT");
	}

	/* parse CGI data */
	for (x = 0; cl[0] != '\0' && x < ENTSIZ; x++) {
		m = x;
		getword(entries[x].val, cl, '&');
		plustospace(entries[x].val);
		unescape_url(entries[x].val);
		nltospace(entries[x].val);
		getword(entries[x].name, entries[x].val, '=');
	}
	object[0] = '\0';
	for (x = 0; x <= m && x < ENTSIZ; x++) {
		if (memcmp(entries[x].name, "object", 6) == 0)
			strcpy(object, entries[x].val);
		else if (memcmp(entries[x].name, "type", 6) == 0)
			data_type = strdup(entries[x].val);
		else if (memcmp(entries[x].name, "attribute", 6) == 0)
			select_attribute = strdup(entries[x].val);
	}

	/* validity checks */
	if (*object == '\0') {
		fatal_http("Illegal DisplayObject usage.\n");
	}

	if (*object == '/')
		sprintf(objurl, "http://%s:%s%s", sh, sp, object);
	else
		sprintf(objurl, "http://%s:%s/%s", sh, sp, object);

	use_local_cache = 0;
	init_url();
	if ((up = url_open(objurl)) == NULL || url_retrieve(up)) {
		sprintf(errmsg, "Cannot access object: '%s'\n", objurl);
		fatal_http(errmsg);
	}
	htmlify_file(up->filename);
	url_close(up);
	finish_url();
	fflush(stdout);
	do_shutdown(0);
}

static void htmlify_file(filename)
char *filename;
{
	FILE *fp, *ofp;
	char buf[BUFSIZ];
	int n;
	Template *t;
	AVList *walker;
	AVPair *avp;
	struct stat sb;

	if ((fp = fopen(filename, "r")) == NULL) {
		sprintf(errmsg, "fopen: %s: %s\n", filename, strerror(errno));
		fatal_http(errmsg);
	}
	tfile = tempnam(NULL, "dobj");
	if ((ofp = fopen(tfile, "w")) == NULL) {
		sprintf(errmsg, "fopen: %s: %s\n", tfile, strerror(errno));
		fatal_http(errmsg);
	}
	init_parse_template_file(fp);
	if ((t = parse_template()) == NULL) {
		fclose(ofp);
		sprintf(errmsg, "SOIF Object: '%s' is corrupt.\n", filename);
		fatal_http(errmsg);
	}

	if (select_attribute) {
		if ((avp = extract_AVPair(t->list, select_attribute)) != NULL) {
			fwrite(avp->value, 1, avp->vsize, ofp);
		}
	} else {
		/* Now HTML-ify the object */
		fprintf(ofp, "<HTML>\n");
		fprintf(ofp, "<HEAD>\n");
		fprintf(ofp, "<TITLE>SOIF Object for: %s</TITLE>\n", t->url);
		fprintf(ofp, "</HEAD>\n");
		fprintf(ofp, "<BODY>\n");
#ifdef USE_DIRECTORY_LISTING
		do_directory_listing(t, ofp);
#endif
		fprintf(ofp, "<H1><a href=\"/Harvest/brokers/soifhelp.html\">SOIF</a> Object for: %s</H1>\n", t->url);
		fprintf(ofp, "<HR><PRE>\n");
		fprintf(ofp, "@%s { <a href=\"%s\">%s</a>\n", t->template_type,
			t->url, t->url);
		for (walker = t->list; walker; walker = walker->next) {
			if (walker->data->vsize == 0)
				continue;
			fprintf(ofp, "<STRONG>%s</STRONG>{%u}:\t",
				walker->data->attribute,
				(unsigned int) walker->data->vsize);
#ifndef DONT_FORMAT_KEYWORDS
			if (strstr(walker->data->attribute, "eywords"))
				fprintf(ofp, "</PRE><P>\n");
#endif
			fwrite(walker->data->value, 1, walker->data->vsize, ofp);
			fprintf(ofp, "\n");
#ifndef DONT_FORMAT_KEYWORDS
			if (strstr(walker->data->attribute, "eywords"))
				fprintf(ofp, "</P><PRE>\n");
#endif
		}
		fprintf(ofp, "}\n");
		fprintf(ofp, "</PRE>\n");
		fprintf(ofp, "<HR>\n");
		fprintf(ofp, "<ADDRESS>This content summary was generated by the <a href=\"http://harvest.sourceforge.net/\">Harvest</a> system.</ADDRESS>\n");
		fprintf(ofp, "</BODY>\n");
		fprintf(ofp, "</HTML>\n");
	}

	free_template(t);
	finish_parse_template();
	fclose(fp);
	fclose(ofp);

	if (stat(tfile, &sb) < 0) {
		sprintf(errmsg, "stat: %s: %s\n", tfile, strerror(errno));
		fatal_http(errmsg);
	}

	/* write http header */
	if (data_type != NULL)
		printf("Content-type: %s\r\n", data_type);
	else
		printf("Content-type: text/html\r\n");
	printf("Content-length: %ld\r\n\r\n", sb.st_size);
	wrote_http_header = 1;

	if ((fp = fopen(tfile, "r")) == NULL) {
		sprintf(errmsg, "fopen: %s: %s\n", tfile, strerror(errno));
		fatal_http(errmsg);
	}
	while ((n = fread(buf, 1, BUFSIZ - 1, fp)) > 0) {
		alarm(300);	/* kill if write doesn't work in 5 minutes */
		fwrite(buf, 1, n, stdout);
	}
	fclose(fp);
}

#ifdef USE_DIRECTORY_LISTING
static void do_directory_listing(t, ofp)
Template *t;
FILE *ofp;
{
	AVPair *catavp, *pnavp;
	char *buf, *s;
	int i = 0;


	catavp = extract_AVPair(t->list, "category");
	pnavp = extract_AVPair(t->list, "phone-numbers");
	if (catavp == NULL || pnavp == NULL)
		return;

	fprintf(ofp, "<H2>Category: %s</H2>\n", catavp->value);
	fprintf(ofp, "<H2>Phone Numbers</H2>\n");
	fprintf(ofp, "<UL>\n");

	buf = strdup(pnavp->value);
	s = strtok(buf, "\n");
	while (1) {
		if (s == NULL)
			break;
		if (++i > 5) {
			fprintf(ofp, "<HR>\n");
			i = 1;
		}
		fprintf(ofp, "<LI> %s\n", s);
		s = strtok(NULL, "\n");
	}
	fprintf(ofp, "</UL><HR>\n\n");
}
#endif