Helpful Terminal Commands

compression.md

Compression

• tar cf file.tar files - create a tar named file.tar containing files
• tar xf file.tar - extract the files from file.tar
• tar czf file.tar.gz files - create a tar with Gzip compression
• tar xzf file.tar.gz - extract a tar using Gzip
• gzip file - compresses file and renames it to file.gz
• gzip -d file.gz - decompresses file.gz back to file

file-content.md

File Content

• cat file - output the contents of file
• less file - view file with page navigation
• head file - output the first 10 lines of file
• tail file - output the last 10 lines of file
• tail -f file - output the contents of file as it grows, starting with the last 10 lines

file-system.md

File System

• ls - list items in current directory
• ls -l - list items in current directory and show in long format to see perimissions, size, and modification date
• ls -a - list all items in current directory, including hidden files
• ls -F - list all items in current directory and show directories with a slash and executables with a star
• ls dir - list all items in directory dir
• cd dir - change directory to dir
• cd .. - go up one directory
• cd / - go to the root directory
• cd ~ - go to to your home directory
• cd - - go to the last directory you were just in
• pwd - show present working directory
• mkdir dir - make directory dir
• rm file - remove file
• rm -r dir - remove directory dir recursively
• cp file1 file2 - copy file1 to file2
• cp -r dir1 dir2 - copy directory dir1 to dir2 recursively
• mv file1 file2 - move (rename) file1 to file2
• ln -s file link - create symbolic link to file
• touch file - create or update file
• find file - find all instances of file in real system
• locate file - find all instances of file using indexed database built from the updatedb command. Much faster than find

screen-terminal-multiplexer.md

Screen / Terminal Multiplexer

• screen -ls - show your current screen sessions
• CTRL-A - activate commands for screen
• CTRAL-A d - detach from screen session
• screen -x - attach to screen session
• screen -r name - attach to screen session by name
• exit - (inside screen) exit screen session

search-replace.md

Search/Replace

• sed -i 's/day/night/g' file - find all occurrences of day in a file and replace them with night - s means substitude and g means global - sed also supports regular expressions

searching.md

Searching

• grep pattern files - search for pattern in files
• grep -r pattern dir - search recursively for pattern in dir
• grep -rn pattern dir - search recursively for pattern in dir and show the line number found
• grep -r pattern dir --include='*.ext - search recursively for pattern in dir and only search in files with .ext extension
• command | grep pattern - search for pattern in the output of command
• command | grep -A 10 -B 10 pattern - search for pattern in the output of command show 10 lines [A]fter and 10 lines [B]efore
• command | grep -C 10 pattern - search for pattern in the output of command show 10 lines [A]fter and 10 lines [B]efore

shortcuts-bash.md

Shortcuts - Bash

• ctrl+a - move cursor to beginning of line
• ctrl+f - move cursor to end of line
• alt+f - move cursor forward 1 word
• alt+b - move cursor backward 1 word
• ctrl+r - search .bash_history for previously used command