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 Linux command quick reference guide along with meanings (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])
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.