codex-lv2-may-2025

Unix Shell Lessons: Index

1. Create and Organize Files & Folders

Learn to create directories with mkdir, including nested ones, and follow best practices for naming files and folders.

2. Create a Text File Using a Terminal Editor

Use nano to create and edit a plain text file from the command line, and understand how to save and exit properly.

3. Create Files Using the touch Command

Create empty files quickly using touch and learn about filename extensions and conventions.

4. Move and Rename Files Using mv

Rename files or move them between directories using mv, and understand how to avoid overwriting files.

5. Copy Files and Directories Using cp

Duplicate files or entire directories with cp, using the -r flag for recursive copies and comparing it with mv.

6. Remove Files and Directories Using rm

Safely delete files and folders using rm and rm -r, and learn about the risks of permanent deletion without recovery.

7. Work with Multiple Files Using Wildcards and Patterns

Use wildcards like * and ? to copy or list many files at once, and practice organizing and reproducing complex folder structures.

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Key Points

• cp [old] [new] copies a file.
• mkdir [path] creates a new directory.
• mv [old] [new] moves (renames) a file or directory.
• rm [path] removes (deletes) a file.
• * matches zero or more characters in a filename, so *.txt matches all files ending in .txt.
• ? matches any single character in a filename, so ?.txt matches a.txt but not any.txt.
• Use of the Control key may be described in many ways, including Ctrl-X, Control-X, and ^X.
• The shell does not have a trash bin: once something is deleted, it’s really gone.
• Most files’ names are something.extension. The extension isn’t required and doesn’t guarantee anything, but is normally used to indicate the type of data in the file.
• Depending on the type of work you do, you may need a more powerful text editor than Nano.