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95 lines (90 loc) · 3.86 KB
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/*
* Copyright (C) 2002 John Todd Larason <jtl@molehill.org>
*
* 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.
*/
/*
* Overview of an HTTP request:
*
* 1. call hc_start_request() with an URL
*
* hc = hc_start_request("http://192.168.117.3/index.html");
* if (!hc) {error}
*
* Right now the address in the URL must be given as an IP address, not
* a hostname. That's a bug, not a feature.
*
* 2. add any necessary headers with hc_add_req_header; the Host header is
* created automatically; any others, including User-Agent, must be
* explicitely set
*
* if (!hc_add_req_header(hc, "User-Agent", "Mozilla/4.0 (Isn't everything?)") != 0) {error}
*
* 3. send the request; hc_send_request() uses GET, hc_post_request() uses
* POST, with the callback function called repeatedly for the data. It
* should return the number of bytes filled in, and signal end of data by
* returning 0.
*
* if (!hc_send_request(hc)) {error}
*
* 4. check the returned status; 200 is the normal success code, any 2.. code
* is a success of some sort. 3.. codes are redirects, 4.. are errors; see
* the HTTP specs for more information
*
* if (hc_get_status(hc)/100 != 2) {exception of some sort}
*
* 5. Check any response headers you're interested in.
*
* last_modified = hc_lookup_rsp_header(hc, "Last-Modified");
* if (!last_modified) {header wasn't supplied}
*
* 6. read the data; if the item is known to be short, you have the memory for
* it (2x the data length; half of that as a contiguous block), and don't
* mind waiting for all of it, get it all with hc_read_all(). If one of
* conditions doesn't hold, call hc_read_pieces(). The callback function
* is given a buffer to a chunk of data, the amount of data there, and
* a pointer you supply, usually to a structure where it can store state,
* get parameters from the original caller and return information to the
* original caller
*
* if (!(data = hc_read_all(hc))) {error}
*
* Either way, you own the data chunk -- free() it when you're done with it
*
* 7. Clean up
*
* hc_free(hc);
*/
#ifndef HTTPCLIENT_H
#define HTTPCLIENT_H
#include "netclient.h"
#ifdef _WIN32
# define strcasecmp(a, b) strcmp(a, b)
#endif
struct hc;
extern struct hc * hc_start_request(char * url);
extern int hc_add_req_header(struct hc * hc, const char * tag, const char * value);
extern int hc_send_request(struct hc * hc);
extern int hc_post_request(struct hc * hc,
int (*callback)(unsigned char *, size_t, void *),
void * v);
extern int hc_get_status(struct hc * hc);
extern char * hc_lookup_rsp_header(struct hc * hc, const char * tag);
extern unsigned char * hc_read_all_len(struct hc * hc, size_t * plen);
extern unsigned char * hc_read_all(struct hc * hc);
extern int hc_read_pieces(struct hc * hc,
void (*)(unsigned char *, size_t, void *),
void *);
extern int hc_read_pieces_len(struct hc * hc,
void (*)(unsigned char *, size_t, void *),
void *, size_t);
extern void hc_free(struct hc * hc);
#endif