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Linux Commands Cheat Sheet

Table of Contents

In this Linux command line cheat sheet, we will learn:

  • Basic Linux Commands
  • File management user management Linux Commands
  • Programing Linux Commands
  • Job management Filesystem management Linux commands
  • Process management Linux Commands
  • Shortcuts
  • network
  • System Info
  • Searching
  • File Permission

Basic Linux Commands

  • cat Joins and displays files
  • cp Copies files
  • cpio Creates an archive, restores files from an archive, or copies a directory hierarchy
  • cut Selects characters or fields from input lines
  • diff Displays the differences between two text files
  • emacs Editor
  • expand Converts TABs to SPACEs
  • find Finds files based on criteria
  • grep searches for a pattern in files
  • gzip Compresses or decompresses files
  • head Displays the beginning of a file
  • join Joins lines from two files based on a common field
  • less Displays text files, one screen at a time
  • ln Makes a link to a file
  • ls Displays information about one or more files
  • man Displays documentation for utilities
  • mkdir Creates a directory
  • mv Renames or moves a file
  • nl Numbers lines from a file
  • od Dumps the contents of a file
  • paste Joins corresponding lines from files
  • rm Removes a file (deletes a link)
  • sed Edits a file noninteractively
  • sort Sorts and/or merges files
  • split Divides a file into sections
  • tail Displays the last part (tail) of a file
  • tar Stores or retrieves files to/from an archive file
  • touch Creates a file or changes a file’s access and/or modification time
  • uniq Displays unique lines from a file
  • vim Editor
  • wc Displays the number of lines, words, and bytes in one or more files

File management user management Linx Commands

  • cd Changes to another working directory
  • chgrp Changes the group associated with a file
  • chmod Changes the access mode (permissions) of a file
  • chown Changes the owner of a file and/or the group the file is associated with
  • date Displays or sets the system time and date
  • df Displays disk space usage
  • dmesg Displays kernel messages
  • du Displays information on disk usage by directory hierarchy and/or file
  • finger Displays information about users
  • kill Terminates a process by PID
  • killall Terminates a process by name
  • nice Changes the priority of a command
  • nohup Runs a command that keeps running after you log out
  • ps Displays process status
  • renice Changes the priority of a process
  • sleep Creates a process that sleeps for a specified interval
  • stat Displays information about files
  • stty Displays or sets terminal parameters
  • sysctl Displays and alters kernel variables at runtime
  • top Dynamically displays process status
  • umask Specifies the file-creation permissions mask
  • w Displays information about local system users
  • which Shows where in PATH a utility is located
  • who Displays information about logged-in users

Programing Linux Commands

  • configure Configures source code automatically
  • gawk Searches for and processes patterns in a file
  • gcc Compiles C and C++ programs
  • make Keeps a set of programs current
  • mawk Searches for and processes patterns in a file
  • perl Scripting language
  • python Programming language

Job management Filesystem management Linux commands

  • at Executes commands at a specified time
  • cal Displays a calendar
  • crontab Maintains crontab files
  • echo Displays a message
  • expr Evaluates an expression
  • fsck Checks and repairs a filesystem
  • mkfs Creates a filesystem on a device
  • screen Manages several textual windows
  • tee Copies standard input to standard output and one or more files
  • test Evaluates an expression
  • tr Replaces specified characters
  • tty Displays the terminal pathname

Process management Linux Commands

  • bg To send a process to the background
  • fg To run a stopped process in the foreground
  • top Details on all Active Processes
  • ps Give the status of processes running for a user
  • ps PID Gives the status of a particular process
  • pidof Gives the Process ID (PID) of a process
  • kill PID Kills a process
  • nice Starts a process with a given priority
  • renice Changes priority of an already running process
  • df Gives free hard disk space on your system
  • free Gives free RAM on your system

Shortcuts

  • Ctrl+C – halts the current command
  • Ctrl+Z – stops the current command, resume with
  • fg in the foreground or bg in the background
  • Ctrl+D – log out of current session, similar to exit
  • Ctrl+W – erases one word in the current line
  • Ctrl+U – erases the whole line
  • Ctrl+R – type to bring up a recent command
  • !! – repeats the last command
  • exit – log out of current session

Network

  • ping host – ping host and output results
  • whois domain – get whois information for domain
  • dig domain – get DNS information for domain
  • dig -x host – reverse lookup host
  • wget file – download file
  • wget -c file – continue a stopped download
  • ./ – curret directory right now
  • ../ – previous directory
  • ~ – the users home directory
  • | – pipe the output of one command into another
  • > – use command on the following file (overwrite)
  • >> – use command on following file (appends)

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
  • tar cjf file.tar.bz2 – create a tar with Bzip2 compression
  • tar xjf file.tar.bz2 – extract a tar using Bzip2
  • gzip file – compresses file and renames it to file.gz
  • gzip -d file.gz – decompresses file.gz back to file

System Info

  • date – show the current date and time
  • cal – show this month’s calendar
  • uptime – show current uptime
  • w – display who is online
  • whoami – who you are logged in as
  • finger user – display information about user
  • uname -a – show kernel information
  • cat /proc/cpuinfo – cpu information
  • cat /proc/meminfo – memory information
  • man command – show the manual for command
  • df – show disk usage
  • du – show directory space usage
  • free – show memory and swap usage
  • whereis app – show possible locations of app
  • which app – show which app will be run by default

Searching

  • grep pattern files – search for pattern in files
  • grep -r pattern dir – search recursively for pattern in dir
  • command | grep pattern – search for pattern in the output of command
  • locate file – find all instances of file
  • find /dir/ -name name* Find files starting with name in dir
  • find /dir/ -user name Find files owned by name in dir
  • find /dir/ -mmin num Find files modifed less than num minutes ago in dir

File Permissions

  • chmod octal file – change the permissions of file to octal, which can be found separately for user, group, and world by adding
  • 4 – read (r)
  • 2 – write (w)
  • 1 – execute (x)

IO Redirection

  • cmd < file Input of cmd from file
  • cmd1 <(c
    md2) Output of cmd2 as file input to cmd1
  • cmd > file Standard output (stdout) of cmd to file
  • cmd > /dev/null Discard stdout of cmd
  • cmd >> file Append stdout to file
  • cmd 2> file Error output (stderr) of cmd to file
  • cmd 1>&2 stdout to same place as stderr
  • cmd 2>&1 stderr to same place as stdout
  • cmd &> file Every output of cmd to file

Linux Troubleshooting Guide:

Linux Learning Guide: