Common Linux Commands and their Meaning

Article by Apurba Debnath (5,978 pts ) , published Jun 22, 2009

A list of some common Linux commands and their usages.

Learning Linux commands is one of the main concerns for any Linux beginner. Although, the improvement in GUI has made it possible to accomplish almost everything with a graphical interface the fact is you still need to know the Linux command line to get the most out of it. Here’s a list of some of the most used commands along with their meaning (what they do).

ls (Synopsis: s [options] [names])

Lists the contents of a directory.

mkdir (Synopsis: mkdir [OPTION] DIRECTORY)

Creates a (or more than one) new directory.

cp (Synopsis: cp [OPTION]... SOURCE... DIRECTORY)

Copy source to destination (to copy files)

mv (Synopsis: mv [OPTION]... SOURCE... DIRECTORY)

Move/rename files or directories

cal (synopsis: cal [-3jmy] [[month] year])

Displays a calendar

whoami (Synopsis: whoami [OPTION])

Displays the user id of the current user.

Tree (Synopsis: Tree [-OPTIONS])

Lists the contents of directories in a tree structure.

cat (Synopsis: cat [OPTION] [FILE])

Concatenate files.

uptime (Synopsis: Uptime /Uptime [-V])

Displays how long the system has been running.

pwd (Synopsis: pwd [OPTIONS])

Prints the name of the current directory

df (Synopsis: df [OPTION] ..[FILE])

displays disk space usage data

whereis (Synopsis: whereis [ -bmsu ] [ -BMS directory... -f ] filename)

Find the binary, source for specified files.

man (Synopsis: man [options] [section] [title])

Display the on-line reference manual.

Kill (Synopsis: kill [ -signal | -s signal ] pid)

Sends a signal to terminate a (or multiple) process IDs.

mount (Synopsis: mount [-lhV])

Mounts a file system.

grep (Synopsis: grep [OPTIONS] PATTERN [FILE...])

Searches for files matching a regular expression pattern.

chmod (Synopsis: chmod [OPTION]... MODE[,MODE]... FILE)

Changes the file mode bits.

ln (Synopsis: ln [OPTION]... TARGET)

Makes links between files.

top (Synopsis: top [options])

Displays the currently running Linux tasks.

cron (Synopsis: cron [-f] [-l] [-L loglevel])

Execute scheduled commands.

sudo (Synopsis: sudo [options] [command] )

Run a command as another user.

hostname (Synopsis: hostname [option] [nameofhost])

Display/set the host name of the system.

ssh (Synopsis: ssh [options] hostname [command])

A program to log into a remote machine and executing command on the remote machine.

rm (Synopsis: rm [OPTION]... FILE)

Remove specified files or directories.

ps (Synopsis: ps [Options])

Displays a snapshot of the current running processes.

locate (Synopsis: locate [options] pattern)

Search and displays file names matching the specified pattern

find (Synopsis: find [pathnames] [conditions])

Performs a search for files in a directory hierarchy.

w (Synopsis: w[Options] [user])

Displays which user is logged in and what they are doing.