ref: e9e2e37c329dbe98bfeb27a1828ef9a71fa84f88
dir: /src/utils/cst_url.c/
/*************************************************************************/
/* */
/* Language Technologies Institute */
/* Carnegie Mellon University */
/* Copyright (c) 2011 */
/* All Rights Reserved. */
/* */
/* Permission is hereby granted, free of charge, to use and distribute */
/* this software and its documentation without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of this work, and to */
/* permit persons to whom this work is furnished to do so, subject to */
/* the following conditions: */
/* 1. The code must retain the above copyright notice, this list of */
/* conditions and the following disclaimer. */
/* 2. Any modifications must be clearly marked as such. */
/* 3. Original authors' names are not deleted. */
/* 4. The authors' names are not used to endorse or promote products */
/* derived from this software without specific prior written */
/* permission. */
/* */
/* CARNEGIE MELLON UNIVERSITY AND THE CONTRIBUTORS TO THIS WORK */
/* DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING */
/* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT */
/* SHALL CARNEGIE MELLON UNIVERSITY NOR THE CONTRIBUTORS BE LIABLE */
/* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
/* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN */
/* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, */
/* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF */
/* THIS SOFTWARE. */
/* */
/*************************************************************************/
/* Author: Alan W Black (awb@cs.cmu.edu) */
/* Date: November 2011 */
/*************************************************************************/
/* */
/* Support to access (some forms of) url */
/* http: and file: */
/* Should support libcurl if available -- but a simple form if not */
/* */
/* Only support http: if sockets are available */
/* */
/*************************************************************************/
#include "cst_math.h"
#include "cst_file.h"
#include "cst_string.h"
#include "cst_tokenstream.h"
#include "cst_socket.h"
#ifndef CST_NO_SOCKETS
#ifndef _MSC_VER
#include <stdlib.h>
#include <unistd.h>
#else
#include <io.h>
#include <WinSock.h>
#endif
#endif
int cst_urlp(const char *url)
{
/* Return 1 if url is a url, 0 otherwise */
/* This is decided by the initial substring being "http:" or "file:" */
if ((cst_strlen(url) > 4) &&
(cst_streqn("http:",url,5) ||
cst_streqn("file:",url,5)))
return TRUE;
else
return FALSE;
}
cst_file cst_url_open(const char *url)
{
/* Always opens it for reading */
cst_tokenstream *urlts;
const cst_string *protocol;
int port;
cst_string *host;
int fd;
char *url_request;
char *path;
cst_file ofd;
int state,n;
char c;
urlts = ts_open_string(url, "", ":/", "", "");
protocol = ts_get(urlts);
if (cst_streq(protocol,"http"))
{
#ifdef CST_NO_SOCKETS
ts_close(urlts);
return NULL;
#else
if (!cst_streq(ts_get(urlts),":") ||
!cst_streq(ts_get(urlts),"/") ||
!cst_streq(ts_get(urlts),"/"))
{
ts_close(urlts);
return NULL;
}
host = cst_strdup(ts_get(urlts));
if (cst_streq(ts_get(urlts),":"))
port = (int)cst_atof(ts_get(urlts));
else
port = 80;
/* Open port to web server */
fd = cst_socket_open(host,port);
if (fd < 0)
{
cst_free(host);
ts_close(urlts);
return NULL;
}
url_request = cst_alloc(char,cst_strlen(url)+17);
cst_sprintf(url_request,"GET %s HTTP/1.2\n\n",url);
n = write(fd,url_request,cst_strlen(url_request));
cst_free(url_request);
/* Skip http header -- until \n\n */
state=0;
while (state != 4)
{
n=read(fd,&c,1);
if (n == 0)
{ /* eof or link gone down */
cst_free(host);
ts_close(urlts);
return NULL;
}
if ((state == 0) && (c == '\r'))
state=1;
else if ((state == 1) && (c == '\n'))
state=2;
else if ((state == 2) && (c == '\r'))
state=3;
else if ((state == 3) && (c == '\n'))
state=4;
/* Not sure you can get no CRs in the stream */
else if ((state == 0) && (c == '\n'))
state=2;
else if ((state == 2) && (c == '\n'))
state=4;
else
state = 0;
}
ofd = fdopen(fd,"rb");
ts_close(urlts);
cst_free(host);
return ofd;
#endif
}
else if (cst_streq(protocol,"file"))
{
if (!cst_streq(ts_get(urlts),":") ||
!cst_streq(ts_get(urlts),"/") ||
!cst_streq(ts_get(urlts),"/"))
{
ts_close(urlts);
return NULL;
}
path = cst_strdup(&urlts->string_buffer[urlts->file_pos-1]);
/* printf("awb_debug fileurl %s\n",path); */
ofd = cst_fopen(path,CST_OPEN_READ);
ts_close(urlts);
cst_free(path);
return ofd;
}
else
{ /* Unsupported protocol */
return NULL;
}
}