UNIX common commands

This quick guide lists the commands, including syntax and brief instructions. For more details, use -

$man command

Files and directories

These commands allow you to create directories and process files.

Command	Describe
cat	Displays the contents of the file
Cd	Change the directory to the directory name
chgrp	Change the file group
chmod	Change permissions
Cp	Copy the source file to the destination
file	Determine the file type
find	Find the file
Grep	The regular expression for the search file.
head	Displays the first few lines of the file
ln	Create a soft link that uses oldName
Ls	Displays information about the file type.
Mkdir	Create a new directory directory name
more	The data is displayed as a page.
Mv	Move (rename) using oldName for newame.
Pwd	Print the current working catalog.
Rm	Delete (delete) the file name
rmdir	Delete the existing directory as long as it is empty.
tail	Finally, print a few lines in the file.
touch	The time at which the file was accessed and modified.

The contents of the file can be compared and changed with the following command.

Command	Describe
Awk	Mode scans and processes the language
Cmp	Compare the contents of the two files
comm	Compare sorted data
cut	Cut out the selected fields on each line of a file
Diff	Differential file comparison
expand	Extended tabs are spaces
join	Add some common field files
Perl	Data manipulation language
Sed	Stream text editor
sort	Sort file data
split	The file is split into smaller files
Tr	Translate characters
uniq	A file that reports duplicate lines
Wc	count the words, lines and characters
Ⅵ	Open the vi text editor
Vim	Open the VIM text editor
Fmt	Simple text formatting
spell	Check for misspelled text
ispell	Check for misspelled text
ispell	Check for misspelled text
Emacs	GNU Emacs project
ex，exit	Line editor

Files can be compressed to save space. Compressed files can be created and checked -

Command	Describe
compress	The file is compressed
gunzip	gzip compresses the extracted file
Gzip	GNU replaces compression
uncimpress	Unzip the file
unzip	List, test and extract ZIP archives of compressed files
zcat	Unzip the file
zcmp	Compare compressed files
zdiff	Compare compressed files
zmore	Read through the CRT view of the file filter compressed text

Various UNIX manuals and documentation are available online. The following shell command gives the message -

Command	Describe
apropos	The command to find keywords by targeting
info	The display command information page is online
man	Show the man page online
whatis	Search full name search whatis database.
Yelp	GNOME Help Browser

These commands are used to send and receive files from local UNIX hosts to remote hosts around the world.

Command	Describe
Ftp	The file transfer program
Rcp	A copy of the remote file
rlogin	Remotely log on to the UNIX host
rsh	Remote shell
Tftp	Simple file transfer program
Telnet	Let the connection to another host terminal
Ssh	Secure shell terminal or command connection
Scp	Secure shell remote file copy
sftp	Secure shell file transfer program

Some of these commands can be restricted for security reasons on your PC.

The UNIX system supports on-screen information to other users and emails from around the world -

Command	Describe
evolution	Mail processing tool in Linux GUI
mail	Simple e-mail program for sending or reading e-mail messages
mesg	Messages that are allowed or rejected
parcel	Send the file to another user
pine	Based on the VDU-mail tool
talk	with other users
write	Write information to other users

The following programming tools and languages are based on what is installed on your Unix which are available.

Command	Describe
Dbx	SUN debugger
Gdb	GNU debugger
make	Maintain program groups and compilers.
nm	Print the list of programs
size	The size of the print program
strip	Remove the symbol table and relocation bits
Cb	C program beautification
Cc	The ANSI C compiler is the Sun SPARC system
ctrace	C program debugger
Gcc	GNU ANSI C compiler
indent	Indent and format C program source code
Bc	Interactive arithmetic language processor
gcl	GNU Common Lisp
Perl	The common language
Php	Web embedded language
py	Python language interpreter
Asp	Web embedded language
Cc	The C-compiler is the Sun SPARC system
g ++	GNU C s compiler
javac	Java compiler
appletvieweir	JAVA small program viewer
netbeans	The Java integrated development environment is on Linux
sqlplus	Run Oracle SQL Interpretation
sqlldr	Run Oracle SQL Data Load
Mysql	Run the MySQL SQL explanation

These commands list or change information about the system -

TD.gt; group

Command	Describe
chfn	Change your finger information
chgrp	Change group ownership of the file
chown	Change the owner
date	The print date
determin	The terminal type is automatically found
du	The amount of print used by the disk
echo	The standard option for echo parameters
exit	Exit the system
finger	Print information about the signed-in user
groupadd	Create a user group
Show group members
homequota	Displays quotas and file usage
Iostat	Report I/O statistics
kill	Sends a signal to a process
last	Shows the user's last sign-in
logout	Sign out of UNIX
lun	List userna name or login ID
Netstat	Displays the network status
passwd	Change the user's password
passwd	Change your login password
printenv	The display value of a shell variable
Ps	Displays the status of the current process
Ps	Statistics during printing
quota -v	Displays disk usage and restrictions
reset	Reset terminal mode
script	Keep the terminal session script
script	The output of a saved instruction or procedure
setenv	Set the environment variable
stty	Set the terminal options
time	Time command
top	All system processes are displayed
tset	Set the terminal mode
Tty	Print the current terminal name
umask	Indicates that permissions are given to view the file by default
uname	The display name of the current system
uptime	Gets the system running time
useradd	Create a user account
users	The print name on the user record
Vmstat	Report virtual memory statistics
W	Show what the logged-in user is doing
who	The list of logged-in users