### HTTrack Basic Mirroring with Options

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Demonstrates how to use HTTrack to mirror a website with specific options. This example shows setting the number of simultaneous connections to 4 and allowing traversal up and down the directory structure.

```bash
httrack www.all.net/bob/ -c4 -B
```

--------------------------------

### Mirror Start and End Callbacks

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

Callbacks triggered at the beginning and end of the mirroring process, allowing for setup and finalization.

```APIDOC
## _start_

### Description
Called when the mirror starts. The `opt` structure passed lists all options defined for this mirror. You may modify the `opt` structure to fit your needs.

### Method
Callback

### Endpoint
N/A

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```c
int mycallback(t_hts_callbackarg *carg, httrackp* opt);
```

### Response
#### Success Response (int)
- **1** (int) - Upon success.
- **0** (int) - Upon error (the mirror will then be aborted).

#### Response Example
```
1
```

## _end_

### Description
Called when the mirror ends.

### Method
Callback

### Endpoint
N/A

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```c
int mycallback(t_hts_callbackarg *carg, httrackp* opt);
```

### Response
#### Success Response (int)
- **1** (int) - Upon success.
- **0** (int) - Upon error (the mirror will then be considered aborted).

#### Response Example
```
1
```
```

--------------------------------

### Compile HTTrack Trunk Release

Source: https://github.com/xroche/httrack/blob/master/README.md

This snippet shows how to clone the HTTrack repository, configure the build with a specified installation prefix, and then compile and install the software using make. It assumes a Unix-like environment with git and make installed.

```sh
git clone https://github.com/xroche/httrack.git --recurse
cd httrack
./configure --prefix=$HOME/usr && make -j8 && make install
```

--------------------------------

### HTTrack Command Line with .httrackrc

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Example of running HTTrack with a configuration file and the resulting command line arguments generated based on the .httrackrc settings.

```shell
$ httrack ghost
$ cat hts-cache/doit.log
-c8 -C1 -R2 +\*.gif -ad.doubleclick.net/* ghost
```

--------------------------------

### Cache.zip File Structure Example

Source: https://github.com/xroche/httrack/blob/master/html/cache.html

Example output from `unzip -l` showing the structure of a cache.zip file.

```APIDOC
## Cache.zip File Structure Example

Example of cache file:

```
$ unzip -l hts-cache/new.zip
Archive:  hts-cache/new.zip
HTTrack Website Copier/3.31-ALPHA-4 mirror complete in 3 seconds : 5 links scanned, 
3 files written (16109 bytes overall) [17690 bytes received at 5896 bytes/sec]
(1 errors, 0 warnings, 0 messages)
  Length     Date   Time    Name
 --------    ----   ----    ----
       94  07-18-03 08:59   http://www.httrack.com/robots.txt
     9866  01-17-04 01:09   http://www.httrack.com/html/cache.html
        0  05-11-03 13:31   http://www.httrack.com/html/images/bg_rings.gif
      207  01-19-04 05:49   http://www.httrack.com/html/fade.gif
        0  05-11-03 13:31   http://www.httrack.com/html/images/header_title_4.gif
 --------                   -------
    10167                   5 files
```
```

--------------------------------

### HTTrack Basic Mirroring Command

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

This is a basic example of how to initiate a website mirror using HTTrack. It specifies the URL to mirror and an output directory. The '-N0' option ensures the original directory structure is maintained.

```bash
httrack http://www.shoesizes.com -O /tmp/shoesizes -N0
```

```bash
httrack http://www.shoesizes.com -O /tmp/shoesizes
```

--------------------------------

### HTTrack User Authentication Example

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Shows how to specify a username and password directly in the URL for accessing password-protected websites with HTTrack. This is a basic form of authentication.

```shell
httrack smith:foobar@www.all.net/private/index.html
```

--------------------------------

### Configure HTTrack Cache and Log Options

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Examples of using command-line flags to control caching strategies, log output, and indexing behavior for HTTrack mirroring tasks.

```bash
httrack http://www.shoesizes.com -O /tmp/shoesizes -C0
httrack http://www.shoesizes.com -O /tmp/shoesizes -k
httrack http://www.shoesizes.com -O /tmp/shoesizes -update '%n'
httrack http://www.shoesizes.com -O /tmp/shoesizes -Q
httrack http://www.shoesizes.com -O /tmp/shoesizes -q
httrack http://www.shoesizes.com -O /tmp/shoesizes -z -Z -v
httrack http://www.shoesizes.com -O /tmp/shoesizes -f2
httrack http://www.shoesizes.com -O /tmp/shoesizes -I0
httrack http://www.shoesizes.com -O /tmp/shoesizes %v
httrack http://www.shoesizes.com -O /tmp/shoesizes f2
httrack http://www.shoesizes.com -O /tmp/shoesizes -%I linux.localdomain
```

--------------------------------

### C Callback Example for HTTrack

Source: https://github.com/xroche/httrack/blob/master/html/plug_330.html

An example C function demonstrating how to implement a callback for HTTrack. This function, `process_file`, is designed to be plugged into the 'check-html' callback. It prints the URL being parsed and returns a success code.

```c
int process_file(char* html, int len, char* url_adresse, char* url_fichier) {
  printf("now parsing %s%s..\n", url_adresse, url_fichier);
  strcpy(currentURLBeingParsed, url_adresse);
  strcat(currentURLBeingParsed, url_fichier);
  return 1;  /* success */
}
```

--------------------------------

### Proxy Usage and Maintenance Commands

Source: https://github.com/xroche/httrack/blob/master/html/httrack.man.html

Examples of using a proxy server for crawling and performing maintenance tasks like updating or resuming an existing mirror.

```bash
httrack www.someweb.com/bob/bobby.html --spider -P proxy.myhost.com:8080
httrack --update
httrack --continue
```

--------------------------------

### Execute HTTrack Mirroring via Command Line

Source: https://github.com/xroche/httrack/blob/master/html/cmddoc.html

Demonstrates the basic syntax for invoking the HTTrack executable to mirror a website. It includes examples of specifying target URLs and applying configuration options such as output directory and proxy settings.

```shell
httrack
httrack www.someweb.com/foo/
httrack www.someweb.com/foo/ -O "/webs" -N4 -P proxy.myhost.com:3128
```

--------------------------------

### HTTrack Configuration (.httrackrc) Examples

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Illustrates different ways to configure HTTrack options using the .httrackrc file. This includes setting socket connections, retries, user agent, proxy, and defining include/exclude filters.

```ini
set sockets 8
set retries 4
index on
set useragent "Mozilla [en] (foo)"
set proxy proxy:8080
```

```ini
set sockets=8
set index on
retries=2
allow \*.gif
den y ad.doubleclick.net/*
```

```ini
sockets=8
index=1
retries=2
allow=\*.gif
den y=ad.doubleclick.net/*
```

```ini
allow \*.gif
allow \*.jpg
```

```ini
allow=\*.gif
allow=\*.jpg
```

--------------------------------

### HTTrack Mirror Start and End Callbacks (C)

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

Callbacks executed when an HTTrack mirror process begins and concludes. The 'start' callback receives the options structure, which can be modified. The 'end' callback is called upon completion, and its return value indicates success or failure.

```c
int mycallback(t_hts_callbackarg *carg, httrackp* opt);
```

```c
int mycallback(t_hts_callbackarg *carg, httrackp* opt);
```

--------------------------------

### HTTrack Plugin Initialization Callback (C)

Source: https://github.com/xroche/httrack/blob/master/html/plug_330.html

This function is called if the optional libhttrack-plugin module is found. It allows the setup of callbacks using htswrap_add. This is the entry point for initializing plugins loaded by HTTrack.

```c
void plugin_init(void);
```

--------------------------------

### HTTrack Filter Syntax Examples

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Demonstrates various HTTrack filter patterns for including or excluding URLs based on patterns, file types, and sizes. These filters are crucial for controlling which parts of a website are mirrored.

```shell
-www.all.net/*
+\*.com/*
-*.cgi-bin/*
+\*.com/*[path].zip
-*.someweb/*.tar*
+\*/*somepage*
-*.html
+\*.html*[]
-*.gif*["> 5"] -*.zip +*.zip*["< 10"]
```

--------------------------------

### Cache.zip Meta-data Example

Source: https://github.com/xroche/httrack/blob/master/html/cache.html

Example of meta-data stored within a cache.zip file entry, mimicking HTTP headers.

```APIDOC
## Cache.zip Meta-data Example

Example of cache file meta-data:

```
HTTP/1.1 200 OK
X-In-Cache: 1
X-StatusCode: 200
X-StatusMessage: OK
X-Size: 94
Content-Type: text/plain
Last-Modified: Fri, 18 Jul 2003 08:59:11 GMT
Etag: "40ebb5-5e-3f17b6df"
X-Addr: www.httrack.com
X-Fil: /robots.txt
```
```

--------------------------------

### Configure Directory Traversal and Scope

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Examples of using HTTrack flags to control how the mirror utility navigates directory structures and domains, such as staying within a directory, going up/down, or restricting to specific domains.

```bash
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -S
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -D -n
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -U
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -B
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -a
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -d
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -l
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -e
httrack http://www.shoesizes.com/bob/ -O /tmp/shoesizes -'%H'
```

--------------------------------

### Implement Temporary IP Bans

Source: https://github.com/xroche/httrack/blob/master/html/abuse.html

This example demonstrates how to temporarily block an IP address using system-level firewall rules (ipchains) when suspicious activity is detected. It requires root privileges and is intended for Linux environments.

```php
<?php
// Add IP.
add_temp_firewall_rule($REMOTE_ADDR,"30s");
?>
function add_temp_firewall_rule($addr) {
    // The chain chhttp is flushed in a cron job to avoid ipchains overflow
    system("/usr/bin/sudo -u root /sbin/ipchains -I 1 chhttp -p tcp -s ".$addr." --dport 80 -j REJECT");
    syslog("user rejected due to too many copy attemps : ".$addr);
}
```

--------------------------------

### Configure HTTrack Mirroring Limits

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Examples of using various HTTrack flags to control the scope and resource usage of a website crawl. These commands demonstrate setting directory depth, file size constraints, total transfer limits, and bandwidth throttling.

```bash
httrack http://www.shoesizes.com -O /tmp/shoesizes -r50
httrack http://www.shoesizes.com -O /tmp/shoesizes -m50000000
httrack http://www.shoesizes.com -O /tmp/shoesizes -m50000000,100000
httrack http://www.shoesizes.com -O /tmp/shoesizes -M1000000000
httrack http://www.shoesizes.com -O /tmp/shoesizes -E3600
httrack http://www.shoesizes.com -O /tmp/shoesizes A100000000
httrack http://www.shoesizes.com -O /tmp/shoesizes -G100000000
httrack http://www.shoesizes.com -O /tmp/shoesizes %e5
```

--------------------------------

### Search HTML Files on a Website with HTTrack

Source: https://github.com/xroche/httrack/blob/master/html/scripting.html

This example demonstrates how to search for a pattern (e.g., 'TITLE') within all HTML files on a website. The '--skeleton' option is used to process files without downloading them entirely. The '-V' option executes a grep command on each file, and the first version echoes matches, while the second attempts to stop processing after the first match.

```bash
httrack --skeleton http://localhost/ -V "if grep -iE \"TITLE\" \"\$0\">/dev/null; then echo \"Match found at \$0\"; fi" rm -rf tmpget
```

```bash
httrack --skeleton http://localhost/ -V "if grep -iE \"TITLE\" \"\$0\">/dev/null; then echo \"Match found at \$0\"; kill -9 \$PPID; fi" rm -rf tmpget
```

--------------------------------

### HTTrack File Naming with Query String Hashing

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

This example demonstrates how HTTrack handles filenames when URLs contain query parameters. The %q option hashes the query string and appends it to the filename, which is useful for distinguishing between files with identical names but different parameters, preventing potential hash collisions.

```bash
%h%p/%n%q.%t
```

--------------------------------

### Initialize HTTrack C Library

Source: https://context7.com/xroche/httrack/llms.txt

Demonstrates the basic lifecycle of the HTTrack C library, including initialization, option configuration, and execution of a mirror task.

```c
#include "httrack-library.h"
#include "htsopt.h"
#include "htsdefines.h"

int main(int argc, char **argv) {
    httrackp *opt;

    // Initialize the library
    hts_init();

    // Create options structure
    opt = hts_create_opt();

    // Run mirror with command-line style arguments
    char *args[] = {"httrack", "www.example.com", "-O", "/output/path", NULL};
    int result = hts_main(4, args);

    // Or use hts_main2 with explicit options
    result = hts_main2(argc, argv, opt);

    // Clean up
    hts_free_opt(opt);
    hts_uninit();

    return result;
}
```

--------------------------------

### Basic HTTrack Mirroring Command

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Demonstrates the simplest syntax to initiate a website mirror using default settings. The command takes a URL as an argument and applies the default configuration marked with asterisks in the tool's help menu.

```bash
httrack http://www.all.net/bob/
```

--------------------------------

### Basic Website Mirroring with HTTrack

Source: https://github.com/xroche/httrack/blob/master/html/httrack.man.html

Demonstrates the fundamental usage of HTTrack to mirror a specific website to a local directory.

```bash
httrack www.someweb.com/bob/
```

--------------------------------

### Module Initialization and Wrapper Functions

Source: https://github.com/xroche/httrack/blob/master/html/plug_330.html

Functions for initializing modules and wrappers, handling arguments, and setting up callbacks.

```APIDOC
## Module Initialization and Wrapper Functions

### `_module function name_`

### Description
Called when a function named **function-name** is extracted from the current module (same as `wrapper_init`). The optional `args` provides additional commandline parameters. Returns 1 upon success, 0 if the function should not be extracted.

### `wrapper_init`

### Description
Called when a function named `fname` is extracted from the current module. The optional `args` provides additional commandline parameters. Besides, use of `htswap_add` (see `httrack-library.h`) is permitted inside this function to setup other callbacks. Returns 1 upon success, 0 if the function should not be extracted.

### `wrapper_exit`

### Description
Called when the module is unloaded. The function should return 1 (but the result is ignored).

### Function Signatures
`int **function-name**_init(char *args);`
`int wrapper_init(char *fname, char *args);`
`int wrapper_exit(void);`
```

--------------------------------

### HTTrack Advanced Filtering for File Inclusion/Exclusion

Source: https://github.com/xroche/httrack/blob/master/html/faq.html

This example demonstrates a more complex filtering scenario in HTTrack. It aims to retrieve only specific file types (HTML, GIF, JPG) from a website while excluding all others.

```bash
httrack www.someweb.com/index.html -* +www.someweb.com/*.htm* +www.someweb.com/*.gif +www.someweb.com/*.jpg
```

--------------------------------

### HTTrack C Plugin: Compilation and Usage

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

This section provides instructions on how to compile the HTTrack C plugin module into a shared library and how to load it using the HTTrack command-line interface. It demonstrates the gcc command for creating the shared object (.so) and the httrack command with the --wrapper option to specify the plugin and optional parameters.

```bash
gcc -O -g3 -shared -o mylibrary.so myexample.c
httrack --wrapper mylibrary http://www.example.com
or, if some parameters are desired:
httrack --wrapper mylibrary,myparameter-string http://www.example.com
```

--------------------------------

### Validate Links with HTTrack

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Commands to verify link integrity on a website. The first example performs a scan without saving files, while the second checks for valid links outside the initial site scope.

```bash
httrack http://www.shoesizes.com -O /tmp/shoesizes -p0
httrack http://www.shoesizes.com -O /tmp/shoesizes -t
```

--------------------------------

### Initialization and Uninitialization Callbacks

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

Callbacks for handling the initialization and uninitialization phases of the HTTrack mirroring process.

```APIDOC
## _init_

### Description
Called during initialization. It is advised to use this callback.

### Method
Callback

### Endpoint
N/A

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```c
void mycallback(t_hts_callbackarg *carg);
```

### Response
#### Success Response (void)
No return value.

#### Response Example
None

## _uninit_

### Description
Called during un-initialization. It is advised to use this callback.

### Method
Callback

### Endpoint
N/A

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```c
void mycallback(t_hts_callbackarg *carg);
```

### Response
#### Success Response (void)
No return value.

#### Response Example
None
```

--------------------------------

### Plugin Initialization

Source: https://github.com/xroche/httrack/blob/master/html/plug_330.html

Callback function for initializing the optional libhttrack-plugin module.

```APIDOC
## Plugin Initialization

### Description
Called if the module (named `libhttrack-plugin.(so|dll)`) is found in the library path. Use of `htswap_add` (see `httrack-library.h`) is permitted inside this function to setup other callbacks.

### Function Signature
`void plugin_init(void);`
```

--------------------------------

### HTTrack Filtering for Specific File Types

Source: https://github.com/xroche/httrack/blob/master/html/faq.html

This example shows how to use HTTrack's filtering capabilities to include or exclude specific file types during a mirror. It demonstrates including all ZIP files and excluding all MPG files.

```bash
httrack www.someweb.com/someaddress.html +*.zip
```

--------------------------------

### Index Website Keywords with HTTrack

Source: https://github.com/xroche/httrack/blob/master/html/scripting.html

This command indexes a website and generates an 'index.txt' file. The index lists keywords, followed by the number of hits and the location of each occurrence in specific pages. It also provides a total hit count for each keyword.

```bash
httrack localhost -%I
```

--------------------------------

### HTTrack Get Files Only

Source: https://github.com/xroche/httrack/blob/master/html/fcguide.html

Uses HTTrack to download files directly without parsing HTML for URLs. Files are saved in the current directory, making it suitable for collecting isolated files or small collections where organization is not critical.

```bash
httrack -g www.mydrivers.com/drivers/windrv32.exe
```

--------------------------------

### HTTrack Wrapper Initialization Callback (C)

Source: https://github.com/xroche/httrack/blob/master/html/plug_330.html

This callback is invoked when a function is extracted from a module. It receives the function name and optional arguments. It allows setup of other callbacks using htswrap_add. Returns 1 on success, 0 to prevent extraction.

```c
int wrapper_init(char *fname, char *args);
```

--------------------------------

### HTTrack Filtering to Accept Only Specific Links

Source: https://github.com/xroche/httrack/blob/master/html/faq.html

This example shows how to use HTTrack filters to strictly adhere to a defined set of links, preventing the download of unintended files. It uses a combination of excluding all files and then explicitly including desired ones.

```bash
httrack www.foo.com -* +www.foo.com/*
```

--------------------------------

### HTTrack Plugin Entry Point (C)

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

The hts_plug function serves as the module's entry point. It allows for plugging callbacks into HTTrack's options structure using the CHAIN_FUNCTION macro. This function is crucial for initializing and configuring custom plugin behavior.

```c
extern int hts_plug(httrackp *opt, const char* argv);

// Example of plugging a callback:
// CHAIN_FUNCTION(opt, check_html, process, userdef);
```

--------------------------------

### HTTrack Client-Side Form Validation and Navigation

Source: https://github.com/xroche/httrack/blob/master/html/server/step2.html

JavaScript functions to manage form submission, input validation, and keyboard event handling for the HTTrack project setup interface. These functions ensure project names are provided and allow navigation via the Enter key.

```javascript
function do_unload() { } function do_load() { window.status=' '; form.projname.select(); } function key_event(event) { if (event && event.keyCode && (event.keyCode == 13 || event.keyCode == 10)) { form.nextBtn.click(); return false; } return true; } function checkname() { if (form.projname.value != '') { return true; } window.status='${LANG_S1}'; form.projname.select(); return false; } function info(str) { window.status = str; }
```

--------------------------------

### HTTrack Initialization and Uninitialization Callbacks (C)

Source: https://github.com/xroche/httrack/blob/master/html/plug.html

Callbacks for handling the initialization and uninitialization phases of an HTTrack mirror. These functions are called once at the beginning and end of the mirroring process, respectively. They do not return any significant value.

```c
void mycallback(t_hts_callbackarg *carg);
```

```c
void mycallback(t_hts_callbackarg *carg);
```

--------------------------------

### Configure MIME Types with HTTrack Assume Option

Source: https://github.com/xroche/httrack/blob/master/html/faq.html

This option allows you to specify the MIME type for files with certain extensions. This is useful for correctly identifying and handling dynamic content or files with non-standard extensions. For example, you can tell HTTrack to treat .php3 and .asp files as HTML, or to rename .dat files to .zip.

```bash
--assume php3=text/html,asp=text/html
--assume dat=application/x-zip
```

--------------------------------

### Advanced Mirroring with Filters and Depth

Source: https://github.com/xroche/httrack/blob/master/html/httrack.man.html

Shows how to mirror multiple sites, apply inclusion filters for specific file types, and limit the recursion depth of the crawler.

```bash
httrack www.someweb.com/bob/ www.anothertest.com/mike/ +*.com/*.jpg -mime:application/*
httrack www.someweb.com/bob/bobby.html +* -r6
```

--------------------------------

### HTTrack Callback Registration Examples (C)

Source: https://context7.com/xroche/httrack/llms.txt

Register custom functions to be called at various stages of the HTTrack crawling and processing pipeline. These callbacks allow for deep customization of mirroring behavior, HTML parsing, link handling, file operations, HTTP requests, and custom file type parsing. The return value of callbacks typically indicates success (1) or failure/abort (0).

```c
// Callback registration examples
CHAIN_FUNCTION(opt, init, my_init, userdata);           // Initialization
CHAIN_FUNCTION(opt, uninit, my_uninit, userdata);       // Cleanup
CHAIN_FUNCTION(opt, start, my_start, userdata);         // Mirror starts
CHAIN_FUNCTION(opt, end, my_end, userdata);             // Mirror ends
CHAIN_FUNCTION(opt, chopt, my_chopt, userdata);         // Options changed

// HTML processing callbacks
CHAIN_FUNCTION(opt, preprocess, my_preprocess, userdata);   // Before parsing
CHAIN_FUNCTION(opt, postprocess, my_postprocess, userdata); // After parsing
CHAIN_FUNCTION(opt, check_html, my_check_html, userdata);   // Decide to parse

// Link handling callbacks
CHAIN_FUNCTION(opt, check_link, my_check_link, userdata);   // Accept/reject URL
CHAIN_FUNCTION(opt, check_mime, my_check_mime, userdata);   // Check MIME type
CHAIN_FUNCTION(opt, linkdetected, my_linkdetected, userdata); // Link found
CHAIN_FUNCTION(opt, savename, my_savename, userdata);       // Modify save path

// File callbacks
CHAIN_FUNCTION(opt, filesave, my_filesave, userdata);       // File saved
CHAIN_FUNCTION(opt, filesave2, my_filesave2, userdata);     // Extended save info
CHAIN_FUNCTION(opt, xfrstatus, my_xfrstatus, userdata);     // Transfer complete

// HTTP callbacks
CHAIN_FUNCTION(opt, sendhead, my_sendhead, userdata);       // Request headers
CHAIN_FUNCTION(opt, receivehead, my_receivehead, userdata); // Response headers

// Parser callbacks (for custom file types)
CHAIN_FUNCTION(opt, detect, my_detect, userdata);           // Detect file type
CHAIN_FUNCTION(opt, parse, my_parse, userdata);

// Callback function signatures:
// int mycallback(t_hts_callbackarg *carg, httrackp* opt, ...);
// Return 1 for success/continue, 0 for error/abort
```

--------------------------------

### Open HTTrack Help Window

Source: https://github.com/xroche/httrack/blob/master/html/start.html

A JavaScript snippet used to open the HTTrack documentation in a new browser window with specific UI configurations. It ensures the help window is resizable and includes scrollbars for better navigation.

```javascript
window.open("index.html","WinHTTrackHelp","toolbar=yes,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes");
document.close();
window.close();
```