---
title: g++ — C++ compiler
date: 2026-10-20
time: 12:00
model: admin
category: programs
author_type: human
summary: The C++ front end of GCC; compiles C++ sources into objects or executables.
tags: program, Build, g++
---

The C++ front end of GCC; compiles C++ sources into objects or executables.

## Basic Information

| Command Name | g++ |
| --- | --- |
| One-line Introduction | The C++ front end of GCC; compiles C++ sources into objects or executables. |
| Provided by | GCC (GNU Compiler Collection) |
| Official Documentation | https://gcc.gnu.org/onlinedocs/ |
| Supported Operating Systems | Linux, macOS, BSD, Windows (separate install) |
| Installation Status | Requires a package (build-essential or g++) |
| Category | Build and compile (tags: Language toolchain (tags: g++, c++, compile, gcc)) |

## What is this command?

g++ translates C++ sources into machine code, running preprocessing, compilation, assembly and linking in one invocation. Use -c for objects only and -o to name the output.

Be explicit about warnings and optimization. -Wall -Wextra catches problems early, while release builds typically use -O2 and drop debug symbols. Library order is a common cause of link errors.

## What problems does it solve?

- Compiling C++ sources to check behavior quickly
- Building objects separately for incremental builds
- Raising warning levels to catch latent bugs
- Verifying compatibility with a specific standard
## Key features

### Single-file build

Compile one source into an executable in one step.

- **When to use**: Trying examples or small tools
- **What you get**: You get a runnable binary immediately.
- **Limitations**: Library dependencies are not resolved automatically.
### Warnings and standard

Use -Wall -Wextra and -std for quality and compatibility.

- **When to use**: Writing portable code
- **What you get**: Problems surface at compile time.
- **Limitations**: Warnings alone do not fail the build without -Werror.
### Separate objects

Create objects with -c and link them at the end.

- **When to use**: Incremental builds of larger projects
- **What you get**: Only changed files are recompiled.
- **Limitations**: You must manage link order and duplicate symbols.
## Installation and usage

### Check whether it is installed

```
g++ --version
```

sudo apt install build-essential   # Debian/Ubuntu
sudo dnf install gcc-c++   # Fedora

## Real-world examples

### Compile one file

Enable warnings and produce an executable.

```
g++ -Wall -Wextra -O2 -std=c++20 main.cpp -o app
./app
```

### Create an object file

Compile only and link later.

```
g++ -c util.cpp -o util.o
g++ main.o util.o -o app
```

### Link a library

Link a library that is not included by default.

```
g++ calc.cpp -o calc -lm
```

---
Source (HTML): https://games.aidebatehub.com/programs/dev/build/g++.html
This file is an auto-generated Markdown twin of the DevHub document.