ProxyC

rewrite of this repo in C

ProxyC is a high-performance, asynchronous proxy checker and manager written in pure C. Uses sqlite as a unified storage.

By transitioning from synchronous thread-per-proxy pooling to non-blocking I/O, ProxyC can scale to handle thousands of concurrent proxy validations using minimal memory and near-zero CPU overhead.

Status

Finished
Maybe will add some features in the future
This project was orginally made to improve the performance of my already existing script, as well as to learn C.

Features

• Asynchronous Networking: Uses libcurl's multi-interface to check hundreds of proxies concurrently in a single event loop thread, avoiding thread context switching bottlenecks.

• Unified SQLite Backend: A single database table stores everything.

• SQLite Performance: Tuned with pragmas to match RAM-disk write speeds.

• Bulk Import: Imports massive proxy lists inside SQL transactions.

Project Structure

└── strainer-c/
    ├── Makefile
    ├── data/
    │   └── proxies.txt     your initial proxy list, .db is also here
    ├── include/
    │   ├── checker.h
    │   ├── db.h            <- header files
    │   └── parser.h
    ├── list.txt            list of repos to take proxies from
    ├── src/
    │   ├── checker.c       proxt checker
    │   ├── db.c            sqlite
    │   ├── main.c          cli
    │   ├── parser.c        parsing
    └── strainer            binary, created after `make` cmd

Prerequisites

Ensure you have the necessary development tools and libraries installed on your Unix-like operating system (Linux / macOS):

• gcc or clang
• make
• libcurl
• sqlite3

Installing Dependencies

On Ubuntu/Debian:

sudo apt update
sudo apt install build-essential libcurl4-openssl-dev libsqlite3-dev

On macOS (via Homebrew):

brew install curl sqlite

Building the Project

Compiling the project is automated using the Makefile:

make

This generates the standalone binary executable named strainer.

To clean up compiled object files and binaries:

make clean

CLI Usage

Usage:
  ./strainer --import  <file>                Import proxies
  ./strainer --check                         Check unchecked proxies
  ./strainer --retry                         Retry failed proxies
  ./strainer --export  <file> [--scheme X]   Export active proxies
  ./strainer --stats                         Show statistics

Options:
  --db      <path>   SQLite DB path     (default: data/proxies.db)
  --threads <n>      Concurrent conns   (default: 512)
  --timeout <n>      Timeout seconds    (default: 10)
  --url     <url>    Test URL           (default: http://httpbin.org/get)
  --scheme  <s>      Scheme filter for --export (e.g. socks5://)

Database

CREATE TABLE IF NOT EXISTS proxies (
    id           INTEGER PRIMARY KEY AUTOINCREMENT,
    address      TEXT UNIQUE NOT NULL,       
    status       TEXT NOT NULL DEFAULT 'unchecked', 
    error_type   TEXT DEFAULT NULL,         
    latency_ms   INTEGER DEFAULT NULL,       
    last_checked TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
CREATE INDEX IF NOT EXISTS idx_status ON proxies(status);