CometTextel

Tiny, Elegant, and Practical — A Modern C++ Library for GSM SMS over Serial.

CometTextel is a concise, lightweight C++ library for sending and receiving short messages through a GSM modem. It provides a clean serial abstraction, GSM 03.40 PDU encode/decode, and AT-command helpers — built with C++23 and CMake, ready as a shared or static library.

First-time integration: doc/getting-started.md (download Artifact / Release → include & link).

Features

• Cross-Platform Serial Layer: Unified SerialPort API with Win32 and POSIX backends.
• GSM PDU Codec: 7-bit, 8-bit, and UCS-2 encode/decode without MFC or legacy globals.
• Modem Helpers: Initialize, send (AT+CMGS), list (AT+CMGL), and delete (AT+CMGD) in PDU mode.
• Modern C++23: RAII handles, std::error_code, std::span, and clear public headers under include/comettextel/.
• Shared & Static: Build comettextel as a DLL/shared library and/or a static archive from one CMake tree.
• Multi-Language & Package Ready: Pure C-ABI exports with high-level bindings for C# (.NET / NuGet), Go (Go Packages), Python (PyPI), C/C++, PureBasic, and FreeBASIC.

Limitations

For complete protocol limits, payload capacity tables, and edge-case handling, see doc/limitations.md.

Environment

• Windows 10/11, Linux, or macOS
• CMake 3.28 above (recommend)
• A C++23 compiler (MSVC 19.4x+, GCC 14+, or Clang 18+)
• A GSM modem / USB dongle that speaks AT commands in PDU mode

How to Build

Building requires CMake and a C++23 toolchain. Tested under Windows 11 with MSVC.

cmake -S . -B build -A x64
cmake --build build --config Release

Optional flags:

Option	Default	Description
COMETTEXTEL_BUILD_SHARED	ON	Build the shared library
COMETTEXTEL_BUILD_STATIC	ON	Build the static library
COMETTEXTEL_BUILD_EXAMPLES	ON	Build example programs
COMETTEXTEL_BUILD_TESTS	ON	Build unit tests
COMETTEXTEL_BUILD_DOCS	OFF	Generate Doxygen docs
COMETTEXTEL_BUILD_C_API	ON	Build stable C ABI (c_api.h) for P/Invoke / NuGet

Artifacts (Release):

• Windows: build/Release/comettextel.dll, build/Release/comettextel_static.lib
• Unix: libcomettextel.so / libcomettextel.a
• Example: build/examples/Release/comettextel_*_example.exe

Run unit tests:

cmake --build build --config Release
ctest --test-dir build -C Release --output-on-failure

Install & find_package

cmake -S . -B build -A x64 -DCOMETTEXTEL_BUILD_EXAMPLES=OFF
cmake --build build --config Release
cmake --install build --config Release --prefix ./prefix

Consumer project:

find_package(comettextel 1.0 REQUIRED CONFIG)
target_link_libraries(app PRIVATE comettextel::comettextel)
# or explicitly:
# target_link_libraries(app PRIVATE comettextel::shared)
# target_link_libraries(app PRIVATE comettextel::static)

Set CMAKE_PREFIX_PATH to the install prefix if needed.

API Example

#include "comettextel/comettextel.hpp"

#include <iostream>

int main()
{
    comettextel::GsmModem modem;
    comettextel::SerialConfig config;
    config.baud_rate = 115200;

    if (const auto ec = modem.open_and_init("COM3", config); ec) {
        std::cerr << "open/init failed: " << ec.message() << '\n';
        return 1;
    }

    comettextel::Message message;
    message.service_center = "886932000000";
    message.peer_address = "886912345678";
    message.coding = comettextel::DataCoding::Ucs2;
    message.user_data = "Hello from CometTextel";

    if (const auto ec = modem.send_message(message); ec) {
        std::cerr << "send failed: " << ec.message() << '\n';
        return 2;
    }

    return 0;
}

Examples

Send one UCS-2 SMS:

comettextel_send_example COM3 886932000000 886912345678 "Hello"

List stored messages (summary):

comettextel_list_example COM3

Read the inbox (full text; optional wait for +CMTI):

comettextel_receive_example COM3
comettextel_receive_example COM3 15

Delete one stored message by index:

comettextel_delete_example COM3 1

Layout

comettextel/
├── cmake/                 # Compiler options, Doxygen, package config
├── doc/                   # User guides
│   └── getting-started.md
│   └── limitations.md
│   └── releases.md
│   └── ci.md
├── examples/              # Sample programs (+ c_api_example.c)
├── include/comettextel/   # Public headers (+ c_api.h)
├── nuget/CometTextel.NET/ # Optional .NET NuGet wrapper (P/Invoke; win+linux RID)
├── scripts/               # CI helpers (e.g. stage_c_sdk)
├── sdk/c/                 # C SDK package README template
├── sdk/python/            # Python ctypes PDU + modem (pytest + wheels in CI)
├── sdk/go/                # Go PDU + modem sample (Windows amd64, local verify.ps1)
├── sdk/purebasic/         # PureBasic PDU + modem sample (local verify.ps1)
├── sdk/freebasic/         # FreeBASIC PDU + modem sample (local verify.ps1)
├── src/                   # Library sources
│   └── serial/            # Win32 / POSIX backends
├── tests/                 # Unit tests (CTest)
└── CMakeLists.txt

History

• 2014: Original Win32 COMM / GSM PDU code written as a Visual C++ project.
• 2026: Rewritten as a modern C++23 CMake library with cross-platform serial support and renamed to CometTextel.

Credits

• Original COM port and PDU routines inspired by classic GSM modem programming samples.

License

Copyright (c) 2026 Ji-Feng Tsai.
Code released under the MIT license.

Official Partners & Commercial Editions

This project collaborate with companies that offer commercial versions, hosted services, or enterprise support based on CometTextel:

KJPro Technology - Official Commercial Partner providing enterprise distribution, custom integration, and dedicated support.

TODO

• Modem async I/O / overlapped serial (beyond URC demux + poll queue)
• Vendor modem profiles (CNMI, inbox quirks)
• Concat / incomplete-segment edge cases

Donation

If this library helps you reduce time to coding, you can give me a cup of coffee :)

Paypal Me