CLI framework for C++: cppcli — creating console applications

CLI framework for C++: cppcli — creating powerful console applications

Developing console interfaces (CLI) in C++ often requires manual argument parsing, flag handling, and command organization. The cppcli library provides a ready-made framework for quickly creating professional CLI applications. It allows you to focus on business logic rather than input/output infrastructure. In this article, we will break down the key features of cppcli, provide code examples, and show how to integrate it into your project.

Key features of cppcli

• Declarative command definition — each command is described as a separate class or lambda function.
• Automatic argument parsing — support for positional, named arguments, and flags.
• Colored output and formatting — built-in utilities for styled output (ANSI colors, tables, progress bars).
• Validation and help — automatic generation of help messages and validation of required arguments.
• Extensibility — support for custom argument types and middleware.

Quick start: installation and first example

cppcli is distributed as a header-only library. To install, clone the repository or use CMake FetchContent. Integration into a project:

#include <cppcli/cli.h>#include <iostream>

int main(int argc, char* argv[]) {    cppcli::App app("My application", "1.0.0");    app.run(argc, argv);    return 0;}

This is the minimal skeleton. Now let's add a greet command that takes a user name.

Example: command with arguments

#include <cppcli/cli.h>

int main(int argc, char* argv[]) {    cppcli::App app("Greeter", "1.0.0");

    app.command("greet", "Greets the user")        .argument<std::string>("name", "User name")        .action([](const cppcli::Args& args) {            std::string name = args.get<std::string>("name");            std::cout << "Hello, " << name << "!";        });

    app.run(argc, argv);    return 0;}

Run: ./app greet Ivan will output Hello, Ivan!. If the argument is not specified, cppcli will output an error and help.

Flags and optional parameters

Let's add a --formal flag for a formal greeting:

app.command("greet", "Greets the user")    .argument<std::string>("name", "Name")    .flag("--formal", "-f", "Formal greeting")    .action([](const cppcli::Args& args) {        std::string name = args.get<std::string>("name");        bool formal = args.get<bool>("formal");        if (formal)            std::cout << "Greetings, " << name << "!";        else            std::cout << "Hello, " << name << "!";    });

Now ./app greet Ivan --formal will output Greetings, Ivan!.

Nested commands and subcommands

cppcli supports a tree-like command structure. For example, for a project management utility:

app.command("project", "Project management")    .command("create", "Create a project")        .argument<std::string>("name", "Project name")        .action([](const cppcli::Args& args) {            std::cout << "Project created: " << args.get<std::string>("name") << "";        })    .command("delete", "Delete a project")        .argument<std::string>("name", "Project name")        .flag("--force", "Without confirmation")        .action([](const cppcli::Args& args) {            // deletion logic        });

Call: ./app project