CIS120 Book

CIS120 Linux Fundamentals by Scott Shaper

Keyboard Tricks

Think of keyboard tricks in Linux like having a super-powered keyboard that can do more than just type letters. Just like how video games have special key combinations for special moves, Linux gives you powerful shortcuts to work faster and smarter. These tricks help you type less and do more!

Quick Reference

Category	What It Does	Common Use
Cursor Movement	Move around in commands	Editing commands quickly
Text Editing	Modify text in commands	Fixing typos, changing words
Cut & Paste	Move text around	Reusing parts of commands
Completion	Auto-complete commands	Typing less, working faster
History	Reuse past commands	Running commands again

When to Use Keyboard Tricks

When you need to edit a long command
When you want to reuse parts of commands
When you need to fix typos quickly
When you want to run previous commands
When you need to complete long filenames

Cursor Movement

Think of cursor movement commands like having a teleport button for your cursor. Instead of holding down arrow keys, you can jump to exactly where you need to be!

Key	What It Does	When to Use It
`Ctrl-a`	Go to start of line	When you need to add something at the beginning
`Ctrl-e`	Go to end of line	When you need to add something at the end
`Ctrl-f`	Move forward one character	When you need to move right (same as right arrow)
`Ctrl-b`	Move backward one character	When you need to move left (same as left arrow)
`Alt-f`	Move forward one word	When you need to jump over a word
`Alt-b`	Move backward one word	When you need to jump back a word
`Ctrl-l`	Clear screen	When your screen is cluttered

Text Editing

Think of text editing commands like having a magic eraser and pen. You can fix mistakes, change words, and transform text without retyping everything!

Key	What It Does	When to Use It
`Ctrl-d`	Delete character at cursor	When you need to delete one character
`Ctrl-t`	Swap two characters	When you type letters in wrong order
`Alt-t`	Swap two words	When you type words in wrong order
`Alt-l`	Make word lowercase	When you need to fix capitalization
`Alt-u`	Make word uppercase	When you need to capitalize a word

Cut and Paste (Kill and Yank)

Think of cut and paste commands like having a clipboard for your terminal. You can save parts of commands and use them later!

Key	What It Does	When to Use It
`Ctrl-k`	Cut to end of line	When you want to save the end of a command
`Ctrl-u`	Cut to start of line	When you want to save the beginning of a command
`Alt-d`	Cut to end of word	When you want to save the end of a word
`Alt-Backspace`	Cut to start of word	When you want to save the beginning of a word
`Ctrl-y`	Paste cut text	When you want to use saved text

Command Completion

Think of command completion like having an assistant that finishes your sentences. Just type part of a command and let the computer help you complete it! When you press Tab, the shell tries to complete what you're typing based on what it knows about commands, files, and directories.

How Completion Works

# Basic completion
ls D[TAB] → ls Documents/

# When there are multiple matches, press Tab twice
ls D[TAB][TAB]
Documents/  Downloads/  Desktop/

# When there are many matches (over 100), you'll see:
ls *[TAB]
Display all 150 possibilities? (y or n)

# When there are no matches, you'll hear a beep
ls nonexistent[TAB] → *beep*

Smart Completion Features

Double Tab: When there are multiple possible completions, pressing Tab twice shows all options
Partial Matches: Type enough characters to make the match unique, then Tab
Many Matches: When there are over 100 matches, the shell asks before showing them all
No Matches: The shell beeps to tell you it can't complete what you typed
Case Sensitive: Completion respects case, so 'D' and 'd' are different

Practical Examples

# Type 'ls D' and press Tab
ls Documents/

# Type 'ls D' and press Tab twice to see all D* matches
ls D[TAB][TAB]
Documents/  Downloads/  Desktop/

# Type 'ls *.txt' and press Tab twice to see all .txt files
ls *.txt[TAB][TAB]
file1.txt  file2.txt  file3.txt  ...

# Type 'cd ~/D' and press Tab
cd ~/Downloads/

# When there are many matches, you'll be asked:
ls *[TAB]
Display all 150 possibilities? (y or n)
# Type 'y' to see all matches, 'n' to cancel

Key	What It Does	When to Use It
`Tab`	Complete command/filename	When you know part of a name
`Alt-?`	Show all possibilities	When you want to see all options
`Alt-*`	Insert all possibilities	When you want to use all matches

Command History

Think of command history like having a time machine for your commands. You can go back and reuse any command you've typed before!

Practical Examples

# Run the last command again
!!

# Run command number 88
!88

# Run the last command starting with 'ls'
!ls

# Run the last command containing 'grep'
!?grep

Command	What It Does	When to Use It
`!!`	Run last command	When you want to run the same command again
`!number`	Run command by number	When you know the command number
`!string`	Run last command starting with string	When you remember how the command started
`!?string`	Run last command containing string	When you remember part of the command

Tips for Success

Start with a few basic shortcuts and add more as you get comfortable
Practice using Tab completion - it's a huge time saver
Use command history to avoid retyping long commands
Remember that Alt key combinations might not work in all terminals
Use Ctrl-l to clear your screen when it gets cluttered

Common Mistakes to Avoid

Forgetting that some shortcuts might be different in different terminals
Not using Tab completion when it would save time
Retyping commands that you could get from history
Using arrow keys when keyboard shortcuts would be faster
Not practicing the shortcuts enough to remember them

Best Practices

Learn shortcuts gradually - don't try to memorize them all at once
Use Tab completion whenever possible
Use command history for complex commands
Practice the shortcuts you use most often
Customize your shortcuts if needed (in .bashrc)

Advanced Techniques

Combining Shortcuts

# Edit a long command: Ctrl-a to start, then edit
# Use Alt-f and Alt-b to move by words
# Use Ctrl-k to cut parts you don't need
# Use Ctrl-y to paste them back if needed

# Use history with completion
!ls *.txt  # Run last ls command with .txt files

# Use multiple completions
cd ~/D[TAB]  # Complete to Downloads
ls *.txt[TAB]  # Show all .txt files