# CgeNet - Network Access Library for C

A lightweight, dependency‑free C library providing a consistent interface for
socket operations across POSIX platforms. The library abstracts the low‑level
socket API and offers a unified, easy‑to‑use set of functions for creating,
configuring, and using TCP/UDP sockets.

## Features

- Cross‑platform support (Linux, macOS, Windows)
- IPv4 and IPv6 address handling
- TCP and UDP socket types
- Non‑blocking and blocking mode control
- Simple polling interface for readable / writable events
- Comprehensive error handling with explicit error codes
- Context pointer attached to each socket for user data
- No dynamic memory allocation required by the user (library manages its own
  resources)

## Usage Example

```c
#include "CgeNet.h"
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <stddef.h>

int main(void) {
    int result;

    #ifdef SIGPIPE
    signal(SIGPIPE, SIG_IGN);
    #endif

    if (!CgeNetInit()) {
        fprintf(stderr, "Failed to initialize network");
        return 1;
    }

    CgeNetSocket *sock = CgeNetOpen(CGE_NET_IPV4, CGE_NET_TCP, &result);
    if (!sock) {
        fprintf(stderr, "Failed to open socket: %d\n", result);
        CgeNetCleanup();
        return 1;
    }

    CgeNetAddr addr;
    if (!CgeNetAddrFromStr("127.0.0.1", 8080, &addr)) {
        fprintf(stderr, "Invalid address\n");
        CgeNetClose(sock);
        CgeNetCleanup();
        return 1;
    }

    if (!CgeNetConnect(sock, &addr)) {
        fprintf(stderr, "Connect failed: %d\n", CgeNetErrorCode(sock));
        CgeNetClose(sock);
        CgeNetCleanup();
        return 1;
    }

    const char *msg = "Hello, server!";
    size_t written;
    if (!CgeNetWrite(sock, msg, strlen(msg), &written)) {
        fprintf(stderr, "Write failed: %d\n", CgeNetErrorCode(sock));
        CgeNetClose(sock);
        CgeNetCleanup();
        return 1;
    }

    char buffer[256];
    size_t actual;
    if (CgeNetRead(sock, buffer, sizeof(buffer) - 1, &actual)) {
        buffer[actual] = '\0';
        printf("Received: %s\n", buffer);
    }

    CgeNetClose(sock);
    CgeNetCleanup();

    return 0;
}
```

## Build Systems

- **CMake**: supports Linux, macOS, Windows (MSVC, MinGW)
- **Makefile.posix**: for GCC/Clang on POSIX systems
- **Makefile.mingw**: for MinGW on Windows
- **Makefile.win32**: for MSVC with NMake

Builds a static library. No shared library or external dependencies

## Portability

- **Standard compliance**: written in C89 + `stdint.h`
- **No external dependencies**: only standard C and system socket headers and
  libraries are used
- **Signal handling**: Users of the library should ignore `SIGPIPE` to prevent
  the process from being terminated when writing to a closed socket. This can be
  done once in the application, e.g. `signal(SIGPIPE, SIG_IGN);`

## License

0BSD - a permissive license with no attribution required.