The Most important Linux Commands (With Examples)
Linux is a Open-source popular operating system, and if you want to use this free operating system, you have need to know some basic Linux commands to configure, operate, and interact with your system smoothly.
When you work with Linux operating system, commands are required as inputs to inform or direct a computer program to perform a specific operation. Understanding the most basic Linux commands will allow you to successfully navigate directories, manipulate files, change permissions, display information such as disk space, and more. Obtaining basic knowledge of the most common commands will help you easily execute tasks via the command line.
| Command | Description |
| alias | Create an alias |
| apropos | Search manual for keyword |
| at | Schedule a job to run in the future. |
| awk | Find and Replace text within file(s) |
| break | Exit from a loop |
| builtin | Run a shell builtin |
| bunzip2 | Decompress file from bzip2 format |
| bzip2 | Compress file to bzip2 format |
| cal | Display a calendar |
| case | Conditionally perform a command |
| cat | Concatenate files to standard output |
| cd | Change Directory |
| cfdisk | Partition table manipulator for Linux |
| chgrp | Change group ownership |
| chmod | Change access permissions |
| chown | Change file owner and group |
| chroot | Run a command with a different root directory |
| chvt | Change the virtual Terminal |
| cksum | Print CRC checksum and byte counts |
| clear | Clear terminal screen |
| cmp | Compare two files |
| comm | Compare two sorted files line by line |
| command | Run a command - ignoring shell functions |
| compress | Compress file(s) to old Unix compress format |
| continue | Resume the next iteration of a loop |
| convmv | A perl script that converts filenames from one encoding to another |
| cp | Copy one or more files to another location |
| cron | Daemon to execute scheduled commands at predefined time |
| crontab | Schedule a command to run at a later time |
| csplit | Split a file into context-determined pieces |
| cut | Divide a file into several parts |
| date | Display or change the date & time |
| dc | Desk Calculator |
| dd | Data Dump - Convert and copy a file |
| declare | Declare variables and give them attributes |
| df | Display free disk space |
| diff | Display the differences between two files |
| diff3 | Show differences among three files |
| dir | Briefly list directory contents |
| dircolors | Colour setup for `ls' |
| dirname | Convert a full pathname to just a path |
| dirs | Display list of remembered directories |
| du | Estimate file space usage |
| echo | Display message on screen |
| ed | A line-oriented text editor |
| egrep | Search file(s) for lines that match an extended expression |
| eject | Eject CD-ROM |
| enable | Enable and disable builtin shell commands |
| env | Disp, set, or remove environment variables |
| eval | Evaluate several commands/arguments |
| exec | Execute a command |
| exit | Exit the shell |
| expand | Convert tabs to spaces |
| export | Set an environment variable |
| expr | Evaluate expressions |
| factor | Print prime factors |
| FALSE | Do nothing, unsuccessfully |
| fdformat | Low-level format a floppy disk |
| fdisk | Partition table manipulator for Linux |
| fgrep | Search file(s) for lines that match a fixed string |
| file | Determine type of file |
| find | Search for files that meet a desired criteria |
| fmt | Reformat paragraph text |
| fold | Wrap text to fit a specified width. |
| for | Expand words, and execute commands |
| format | Format disks or tapes |
| free | Disp, s memory usage |
| fsck | Filesystem consistency check and repair. |
| fstat | List open files |
| function | Define Function Macros |
| fuser | Identify process using file |
| gawk | Find and Replace text within file(s) |
| getopts | Parse positional parameters |
| grep | Search file(s) for lines that match a given pattern |
| groups | Print group names a user is in |
| gunzip | Decompress file(s) from GNU zip format |
| gzcat | Show contents of compressed file(s) |
| gzip | Compress file(s) to GNU zip format |
| hash | Remember the full pathname of a name argument |
| head | Output the first part of file(s) |
| history | Command History |
| hostname | Print or set system name |
| iconv | Converts the encoding of characters from one code page encoding scheme to another. |
| id | Print user and group id's |
| if | Conditionally perform a command |
| import | Capture an X server screen and save the image to file |
| info | Help info |
| install | Copy files and set attributes |
| join | Join lines on a common field |
| kill | Stop a process from running |
| less | Display output one screen at a time |
| let | Perform arithmetic on shell variables |
| ln | Make links between files |
| local | Create variables |
| locate | Find files |
| logname | Print current login name |
| logout | Exit a login shell |
| lpc | Line printer control program |
| lpr | Off line print |
| lprint | Print a file |
| lprintd | Abort a print job |
| lprintq | List the print queue |
| lprm | Remove jobs from the print queue |
| ls | List information about file(s) |
| ll | #ls -l List information about file(s) |
| lsof | List open files |
| m4 | Macro processor |
| makewhatis | Rebuild whatis database |
| man | Print manual pages |
| mkdir | Create new folder(s) |
| mkfifo | Make FIFOs (named pipes) |
| mknod | Make block or character special files |
| more | Display output one screen at a time |
| mount | Mount a file system |
| mtools | Manipulate MS-DOS files |
| mv | Move or rename files or directories |
| netconfig | Configure your network |
| nice | Set the priority of a command or job |
| nl | Number lines and write files |
| nohup | Run a command immune to hangup |
| od | View binary files |
| passwd | Modify a user password |
| paste | Merge lines of files |
| pathchk | Check file name portability |
| popd | Restore the previous value of the current directory |
| pr | Convert text files for printing |
| printcap | Printer capability database |
| printenv | Print environment variables |
| printf | Format and print data |
| ps | Process status |
| pushd | Save and then change the current directory |
| pwd | Print Working Directory |
| quota | Display disk usage and limits |
| quotacheck | Scan a file system for disk usage |
| quotactl | Set disk quotas |
| pax | Archive file(s) |
| ram | ram disk device |
| rcp | Copy files between two machines. |
| read | read a line from standard input |
| readonly | Mark variables/functions as readonly |
| remsync | Synchronize remote files via email |
| return | Exit a shell function |
| rm | Remove (delete) files |
| rmdir | Remove folder(s) |
| rpm | RPM Package Manager (was RedHat Package Manager) |
| rsync | Remote file copy (Synchronize file trees) |
| screen | Terminal window manager |
| sdiff | Merge two files interactively |
| sed | Stream Editor |
| select | Accept keyboard input |
| seq | Print numeric sequences |
| set | Manipulate shell variables and functions |
| shift | Shift positional parameters |
| shopt | Shell Options |
| shutdown | Shutdown or restart linux |
| sleep | Delay for a specified time |
| sort | Sort text files |
| source | Run commands from a file `.' |
| split | Split a file into fixed-size pieces |
| strings | print the strings of printable characters in (binary) files. |
| su | Substitute user identity |
| sum | Print a checksum for a file |
| symlink | Make a new name for a file |
| sync | Synchronize data on disk with memory |
| tac | Print files out in reverse line order |
| tail | Output the last part of files |
| tar | Tape ARchiver |
| tee | Redirect output to multiple files |
| test | Evaluate a conditional expression |
| time | Measure Program Resource Use |
| times | User and system times |
| timidity | Play midi files and set up software synth to play midi files with other commands. |
| touch | Change file timestamps |
| top | List processes running on the system |
| traceroute | Trace Route to Host |
| trap | Run a command when a signal is set(bourne) |
| tr | Translate, squeeze, and/or delete characters |
| TRUE | Do nothing, successfully |
| tsort | Topological sort |
| tty | Print filename of terminal on stdin |
| type | Describe a command |
| ulimit | Limit user resources |
| umask | Users file creation mask |
| umount | Unmount a filesystem |
| unalias | Remove an alias |
| uname | Print system information |
| unexpand | Convert spaces to tabs |
| uniq | Uniquify files (remove all duplicate lines) |
| units | Convert units from one scale to another |
| unset | Remove variable or function names |
| unshar | Unpack shell archive scripts |
| until | Execute commands (until error) |
| useradd | Create new user account |
| usermod | Modify user account |
| users | List users currently logged in |
| uuencode | Encode a binary file into 7-bit ASCII characters |
| uudecode | Decode a file created by uuencode |
| v | Verbosely list directory contents (`ls -l -b') |
| vdir | Verbosely list directory contents (`ls -l -b') |
| watch | Execute/display a program periodically |
| whatis | List manual pages by name |
| wc | Print byte, word, and line counts of a file |
| whereis | Report all known instances of a command |
| which | Locate a program file in the user's path. |
| while | Execute commands |
| who | Print all usernames currently logged in |
| whoami | Print the current user id and name (`id -un') |
| xargs | Execute utility, passing constructed argument list(s) |
| yes | Print a string until interrupted |
| zcat | Show contents of compressed file(s) |
| zip | Compress and archive file(s) to zip format |
