proxify

Start a HTTP proxy (on the loopback network interface 127.0.0.1 and port 8888)

$ proxify

$ proxify [[-ha|-http-addr]] "[ip_address]:[port_number]"

$ proxify [[-of|-output-format]] [jsonl|yaml] [[-o|-output]] [path/to/file]

$ proxify -h

proxify [OPTIONS] [command_arguments...]

-t, --type <type>
    Specify the proxy type (e.g., SOCKS4, SOCKS5, HTTP).

-a, --address <host>:<port>
    Specify the proxy server's host address and port number.

-U, --username <user>
    Provide a username for proxy authentication, if required.

-P, --password <pass>
    Provide a password for proxy authentication, if required.

-c, --config <file>
    Use an alternative configuration file for proxy settings instead of default.

-D, --dns
    Force DNS resolution requests to also go through the specified proxy server.

-v, --verbose
    Enable verbose output, showing more details about the proxying process.

-h, --help
    Display a help message with command usage and options, then exit.

The `proxify` command is a conceptual utility designed to execute another command while routing all its network traffic through a specified proxy server (e.g., SOCKS, HTTP). It is not a standard Linux command but rather a common pattern implemented via custom shell scripts or as a wrapper around existing tools like proxychains or tsocks. Its primary purpose is to anonymize connections, bypass geo-restrictions, or access specific network segments by channeling data through an intermediary.

When executed, `proxify` would typically configure the execution environment to ensure that network-aware system calls made by the target command are intercepted and redirected to the proxy. This often involves leveraging mechanisms like LD_PRELOAD to inject a library that hooks network functions. This method provides a powerful way to enforce proxy usage for almost any command-line application, making it invaluable for privacy, security, and network management tasks.

The `proxify` command, being a non-standard concept, is highly dependent on its specific implementation. Most implementations rely on LD_PRELOAD which can have limitations:
1. Non-Standard Nature: It's not a pre-installed Linux command; you'd typically find it as a custom script or part of a specialized tool.
2. Bypass Risks: Applications using static linking, making direct kernel calls, or implementing custom network stacks might bypass the proxy, leading to traffic or DNS leaks.
3. Performance Overhead: Routing traffic through a proxy adds latency and can reduce network performance.
4. Security Concerns: The security of your traffic depends entirely on the trustworthiness of the proxy server.
5. Compatibility: Not all applications may behave correctly when forced through a proxy this way, especially those with complex network interactions.

A hypothetical `proxify` command typically works by modifying the execution environment of the target command. This often involves setting the LD_PRELOAD environment variable to inject a custom shared library (e.g., proxychains.so) into the process space of the command being executed. This injected library then intercepts standard network-related system calls (like connect(), send(), recv(), socket()) made by the target application. Instead of allowing these calls to directly interact with the operating system's network stack, the library redirects them through the configured proxy server. For DNS resolution, it might also intercept functions like getaddrinfo() or gethostbyname() to ensure hostnames are resolved via the proxy, preventing potential DNS leaks.

The primary use case for `proxify` is to execute any network-aware command or script as if its network traffic originates from the proxy server's location. For example, to check your external IP address through a SOCKS5 proxy running on localhost port 9050, you might use:

proxify -t SOCKS5 -a 127.0.0.1:9050 curl ifconfig.me

It's frequently employed with command-line tools that don't natively support proxy settings, for security research, bypassing geo-restrictions, or accessing resources on specific networks without direct routing. It can also be used to chain multiple proxies for enhanced anonymity, depending on the underlying implementation's capabilities.

While not a specific command with a unified history, the concept of 'proxifying' applications on Linux has evolved from basic environment variable settings (like http_proxy) to more sophisticated methods. Tools like tsocks (Transparent SOCKS) and proxychains (initially ProxyChains-3, later proxychains-ng) emerged to provide application-agnostic proxying by leveraging LD_PRELOAD to hook network functions. A 'proxify' script would typically automate and simplify the use of such underlying mechanisms, abstracting away their complexities and providing a consistent command-line interface for users.

proxychains(1), tsocks(1), ssh(1), curl(1), wget(1)