A Step-by-Step Guide: What Happens When You Type "ls *.c" and Hit Enter in Your Shell

When you're just starting out with the command line, even the simplest commands can seem mysterious. So, let's take a closer look at what happens when you type ls *.c and hit Enter in your shell. This command is commonly used for listing all files with the ".c" extension in a directory.

1. Typing the Command:

The first step is to open your terminal or command prompt, and then you type the command:

2. Understanding "ls":

• ls is short for "list" and is a command used for listing files and directories in a directory. When used without any arguments or options, it lists all the files in the current directory.

3. The "*" (Asterisk):

• The asterisk * is a wildcard character that represents zero or more characters. In the context of ls *.c, it's used to match all files with any name ending with ".c."

4. Hitting "Enter":

Once you've entered the command, you press the "Enter" key.

5. Shell Processes the Command:

The shell, which is a command-line interface to your operating system, processes your input. It interprets the command and takes action accordingly.

6. Expanding the Wildcard:

• The shell expands the wildcard *.c before passing the command to the ls command. It searches the current directory for any files that match the pattern.
• For example, if you have files named "file1.c," "example.c," and "code.c," the shell expands *.c to include these files.

7. Executing "ls":

The ls command now receives the expanded command, which might look something like:

8. "ls" Lists the Files:

• The ls command lists the files specified in its arguments. In this case, it lists the files "file1.c," "example.c," and "code.c."
• The output is displayed in your terminal, showing the filenames.

9. Viewing the Results:

You'll now see a list of files with the ".c" extension in your current directory, which can be particularly useful if you're working on C programming projects and want to see all your C source files.

10. Working with the Listed Files:

Once you have the list of files, you can use various commands to manipulate or process them. For example, you can compile your C programs using a command like gcc or perform other operations on these files.

In summary, when you type ls *.c and hit Enter in your shell, you're effectively asking the shell to list all files with a ".c" extension in the current directory. The wildcard * is used to match any characters in the filenames, and the ls command displays the results in your terminal, making it a handy tool for managing and organizing your files.