2023年12月29日金曜日

How to use g++ on command line?

 Here's a guide on using g++ on the command line:

1. Accessing the Command Line:

  • Windows: Open Command Prompt or PowerShell.
  • Linux/macOS: Open Terminal.

2. Checking g++ Availability:

  • Type g++ --version and press Enter. If installed, it'll display the version. If not, install it using your system's package manager.

3. Basic Compilation:

  • Navigate to the directory containing your C++ source file(s) using the cd command.
  • Compile a single file: g++ filename.cpp -o output_filename
    • Replace filename.cpp with your actual file name.
    • The -o flag specifies the output file name.

4. Compiling Multiple Files:

  • g++ file1.cpp file2.cpp -o output_filename
    • List all files to be compiled, separated by spaces.

5. Common Options:

  • -Wall: Enables most warnings to help you catch potential errors.
  • -g: Includes debugging information for using a debugger.
  • -std=c++#: Specifies the C++ language standard to use (e.g., -std=c++17).

6. Linking Libraries:

  • Pass library names after your source files, prefixed with -l: g++ main.cpp -o myprogram -lm -lpthread

7. Including Header Files from Non-Standard Locations:

  • Use the -I flag to specify additional header file search paths: g++ main.cpp -o myprogram -I/path/to/headers

8. Running the Executable:

  • Once compiled successfully, run the executable: ./output_filename

Additional Tips:

  • Use -c to create object files (.o) without linking.
  • Use make for managing complex projects with multiple files and dependencies.
  • Consult g++'s online documentation for more advanced options and features.