gcc vs g++: What's the Difference?

Have you ever thought about the difference between GCC and G++? Well, if I were to answer this in one sentence, it would be "GCC is used to compile C programs whereas G++ is for C++".

But there's a lot more to talk about, such as how you install and use them.

So let's start with the basic introduction.

What is the difference between GCC and G++?

The GCC compiler is used to compile the C programs, whereas the G++ is used for C++ programs. While you could still use GCC to compile C++ program (by using it in gcc -xc++ -lstdc++ -shared-libgcc format, g++ provides a simpler syntax.

Actually, GCC (GNU Compiler Collection) is a super set of various compilers. It has g++ for C++ and GNAT for Ada programming language.

While gcc is capable of compiling C++ programs with help of special flags, you should use g++ instead. The g++ compiler links to standard C++ libraries by default. GCC can also do that but not by default.

Now, let's have a look at the installation.

Installation

Being one of the most essential tools for compiling C and C++ programs in Linux, they both are available in the repositories of all Linux distributions.

Here's how you install it on various Linux distributions:

For Ubuntu/Debian base:

sudo apt install gcc g++

For Fedora/RHEL:

sudo dnf instal gcc g++

For Arch Linux:

sudo pacman -S gcc

(Arch includes G++ in the GCC package itself)

Usage

In this section, I will walk you through how you can compile C and C++ programs using GCC and G++.

To make this guide accessible, I will be using the following C programming code:

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    return 0;
}

And here's the C++ code:

#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

They both should print a simple Hello, World! line.

Compile and run C code

To compile a C program, you can use gcc or g++. If you want to use gcc, here's the syntax that you need to follow:

gcc -o my_program my_program.c

Here,

• -o is used to specify the output file
• my_program is where you specify the name of the output file
• my_program.c is where you append the name of the input file

For example, here's how I compiled my hello.c file using the GCC compiler:

gcc -o hello hello.c

To execute any compiled file, add ./ before the name of the compiled file:

./hello

Similarly, if you want to use G++ to compile the C program, use the following:

g++ -o cpp_program cpp_program.c

Here's how I compiled and ran the same hello.c program with G++:

The && operator is used to run multiple commands but the compilation code will be executed first and then the execution will be done.

Compile and run C++ code

To compile C++ code, you have to use the G++ compiler in the following manner:

g++ -o my_code my_code.cpp

Once done, you can run the code using the executable file:

./my_code

For example, here's how I compiled hello.cpp file using the G++ compiler:

g++ -o hello hello.cpp && ./hello

Next: Here are some important GCC flags

If you are just getting started with the C programming, you are about to use GCC a lot but there are multiple flags that you can use while compiling code.

And here's a detailed guide on important GCC flags:

Important GCC Flags in Linux

You can use GCC flags to extend the functionality of the GCC compiler. Here are some of the common and yet important flags.

Linux HandbookSagar Sharma

I hope you will find this guide helpful.