Unix basic tutorial 3 Communication
1. Internal communication system
2. External communication system
3. Instant messaging
1) chat command write (must be online)
Write username [terminal]
$write npp terminal number (when multiple people log in at the same time)
$write npp
...
Ctrl+d (end)
End of message sending with o (end)
End the conversation with oo (end and exit)
Write command: half-duplex communication
2) message switch command mesg
$mesg n: refuse to receive messages
$mesg y: can receive messages
$mesg
3) two-way communication command talk (full-duplex mode)
Both parties send talk to each other before they can communicate.
The screen is divided into two halves: the top half: the bottom half of the self-input box: the opposite input box
4) broadcast information command wall (write all)
Normal permission issued: only users with mesg open will receive
# wall super users can be forcibly sent to everyone
4. Email (non-timely communication)
1) mail receives mail
Enter mail to enter internal command mode
P: display this email message
S file: save the current message to the file file
M usr: send a new email to user usr
D: delete the current message
N: show the next message
Q: exit
R: reply to email
! Execute the shell command
? : display the internal commands of mail
2) mail username sends email
$mail npp
Subject:test mail
...
Ctrl+d
Cc: CC
Send in a group:
(1) $mail npp1 npp2 npp3
(2) $mail NPP (user group)
(3) Alias
$alias usr_list npp1 npp2 npp3
$mail usr_list
Send attachment:
$mail npp < note.doc sends the file from the direction
Send to users who do not exist:
Return to the dead.letter under the home directory of this user
3) system mailbox: / usr/mail or / var/mail. Such as: / var/mail/npp
4) personal mailbox: mbox file under the user's home directory. / home/npp/mbox
