Linux Commands Cheat Sheet

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:

• Troubleshooting Disk Usage In Linux
• Troubleshooting High Load Average on Linux
• Troubleshoot Network Slow Problems In Linux
• Troubleshoot high iowait issue on Linux

Linux Learning Guide:

• What Is Linux?
• What Is Bash in Linux?
• Linux Commands for Linux Beginners (Cheat Sheet)
• Basic Linux Commands: Linux User Management
• Basic Networking Commands For Ubuntu Linux Interview
• Linux Command: Check Network Status on Linux
• Linux Cat Command with 15 Useful Examples