Utilities

1
Utilities

• User Info Utilities
• Who, w , finger, whoami
• Network Utilities
• talk, write, mail, mailx, rlogin, telnet, ftp
• Other Utilities Spell, compress

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Who is on?

• Who
• W
• Finger
• who am i
• Whoami

3
Finger

• Finger
• Displays all users logged on to your host, their
  real name, terminal, idle times, and login times

4
Finger username

• Finger root
• Find out when the user root last logged on your
  system
• Finger friend_name (username)
• Creat .plan file with info in it to display for
  those who finger you

5
Can I communicate?

• mesg
• Displays yes or no to the question of Can I
  communicate?
• To allow communication, type
• mesg y
• To deny communication, type
• mesg n

6
Talk

• The fastest method of online communication it
  displays letter by letter
• Talk username
• To end communication
• Press Delete
• Or ltCTRLgtC

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write

• Displays communication line by line
• To end communication
• ltCTRLgt D

8
Mailx or mail

• mailx is the advanced version of mail, so it is
  preferable.
• To read your mail, type mail or mailx.
• 3 ways to read a particular message
• 1. Press the no. of message you want to read
• 2. Press t and the no. of message
• 3. Press Enter

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mailx or mail

• To quite reading mail, type q
• To send a mail
• mailx username
• Subject
• The message
• ltCTRLgtD
• To attach a file
• Mailx username lt filename

10
Whereis , which

• To find out if a particular tool or utility
  exists on your system, or where it exists.
• Whereis ping
• Ping /usr/sbin/ping
• Which cat
• /usr/bin/cat

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To test a network connection

• A quick way to verify that a remoter system is
  available, and to check how fast it is
• Ping host_address
• Ping ip addres

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rloginLogging on to a Remote System

• By having access to more than one account, you
  have access to another system that may not be as
  your normal system
• rlogin
• rlogin host_name
• Eg.
• rlogin pollux
• rlogin castor

13
telnetconnecting to a remote system

• Many systems do not allow rlogin connections. You
  can always use telnet utility.
• telnet host_name

14
FTP how to get in FTP

• To transfer or copy file between your account and
  another account, start up ftp by typing
• ftp
• You get the following prompt
• ftpgt
• Means you are in ftp program
• Log on to the remote host by
• Open remote_host_name
• Enter the account name and password

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FTP how to get a file

• After logging in by ftp, you can run ls to see
  what file available
• To get a file from a remote host to your system
• get filename
• To make sure the file has been copied, type
• !ls

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FTP how to put a file in remote host

• To put copies into an account on a remote host
• Put filename
• Check the copy was made
• ls

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Can I specify the file name?

• Yes you can specify the file name in ftp.
• get filename filename.copy
• put filename filename.copy

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How to log out ftp?

• Type the following command to leave ftp
• bye
• Yes, there is no mistake. Just type bye, and you
  are out of ftp.

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Other Useful Utilities

• Spell
• Spell identifies the misspelled words
• Run the following command first
• who head gtgt loginfile
• spell loginfile
• Read the output that appeared on the screen. Are
  there any misspelled words here?!

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Compress

• To compress a file
• compress filename
• To read the compressed file while it is still
  compressed
• zcat compressed_file
• To restore the file to original status
• uncompress filename

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File

• file
• To get information about a file (whether it is
  compressed or not)
• file filename

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hostname

• Determins the name of your remote system, by
  typing
• hostname ltENTERgt

23
!

• If the first two characters of script are !,
  the system interprets the characters that follow
  as the pathname of the program that should
  execute the script.
• !/usr/bin/sh
• !/usr/bin/ksh

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Remember Test II

• Test II
• Next week on the lab