gcc Command: Tutorial & Examples

Compile C files

The gcc command is the GNU Compiler Collection - a set of programming language compilers produced by the GNU Project. It is mainly used to compile and link C and C++ programs, although it has frontends for other programming languages as well.

How it works

The gcc command takes source code files as inputs, then it translates these files into executable programs or libraries. It performs a series of steps: preprocessing, compilation, assembly, and linking to convert your written code into a format that can be run on a computer (machine code).

What it is used for

The gcc command is essential for developing software on Linux, it is used to compile and debug C and C++ programs. It's not just a compiler, it's a complete suite of software development tools that enhance productivity and aid in debugging.

Why it is important

Without gcc, or similar compilers, your written code would just be a text file. gcc makes it possible to execute your code on a computer. It is the bridge between human-readable code and machine-executable instructions.

How to use it

The basic syntax of the gcc command is:

gcc [options] [source files] [object files] [-o output file]

Here are some examples:

  • To compile a file named program.c:

    gcc program.c

    This will create an executable named a.out in the current directory.

  • To compile program.c and name the output program:

    gcc program.c -o program
  • To compile multiple files:

    gcc program1.c program2.c -o program

Common command line parameters

  • -o file: This option is used to specify the name of the output file.
  • -g: This option is used to include debugging information in the executable file.
  • -c: This option is used to compile or assemble, but do not link.
  • -Wall: This option enables all compiler's warning messages.
  • -I directory: This option is used to add the directory to the list of directories to be searched for header files.

Potential problems and pitfalls

Here are some potential problems you might face when using the gcc command:

  • Syntax errors: If your code has syntax errors, the gcc command will fail. You need to fix these errors before you can compile your code.
  • Linking errors: These occur when the linker can't find a library or function that's referenced in your code. Make sure you've installed all the necessary libraries and that they're in the correct location.
  • Runtime errors: Even if your code compiles successfully, it might still have errors that only appear when you run the program. These can be logic errors, like an infinite loop, or resource errors, like running out of memory.
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