Embedded Files
Communication with Other Users
Linux is designed to be a multi-user system, so it is appropriate to have utilities that help users communicate within the system as well as outside the system
For quick communication with users within the system
write
talk
Useful for a quick message between users. The “original” instant messaging tool
Require that both users are currently logged in
Will take over the screen of both users
Since this is not a GUI environment where you can have a window for your work and a different window for messages, when write or talk runs, your work screen will be suspended for messages from write or talk
To communicate with users within the system and outside the system:
mail
This is an email tool
Only the email sender needs to be currently logged in
write
To start write, type: write userID
your work screen is suspended and reserved for write
then you type your line of text message
The other user will:
see on screen a write request message with your userID and your text message
The other user can:
respond by typing write yourID and reply with his/her text message
you both now are running write and can send messages to each other
Or the other user can:
ignore you, in which case you don’t get a message back but you are still in write
you can choose to write another message, or ‘get the hint’ and quit write
To end
control-d
talk
To start talk, type: talk userID
Your work screen is suspended and reserved for talk. It is split into 2 halves, for you and for the other person
Then you type your line of text message
The other user will:
see a talk request message with your userID and your text message
The other user can:
respond by typing talk yourID and reply with his/her text message. His/her screen is also split into 2 halves to show the correspondence
you both are now using talk to send messages
Or the other user can:
ignore you, in which case talk will keep requesting a response from this user until you choose to quit out of talk
To end:
control-c
mesg
To prevent other users from interrupting your work with write or talk, use mesg (for messaging)
2 ways to use mesg
With no argument: mesg
check messaging status, mesg will return:
y which means you can receive messages
n which means you refuse messages
With one argument:
mesg y set messaging to on so you can receive messages (only applies to current session)
mesg n set messaging to off so no messages will get through (only applies to current session)
mail: the “original” email tool. It is only for emailing text and cannot accept attachments
But it is the basic email that comes with every Linux system, so you can use it when “fancier” emails are not / cannot be installed
As with other email tool, and unlike write and talk, the user you send email to doesn’t have to be currently logged in and his/her messaging status doesn’t affect email
2 modes: send and receive
The mail commands in the next slides are either send mode commands or receive mode commands
mail Send Mode: How to Send Mail
Send mode is used to send mail
To start:
mail userID for sending email to a user in the same system
mail full_email_address for sending email to someone outside the system
mail will respond with:
subject: you can fill in the subject or hit enter for no subject
Then start typing the text for your mail message
When done:
control-d to send
mail will respond with cc: you can add addresses for cc, or hit enter to leave it blank
or
control-c to cancel and not send (to “kill” a message in Linux)
you will be asked to do control-c twice to confirm
a message that is killed will be appended to the file dead.letter in your home directory
mail Send Mode: Commands
Send Mode commands:
Each send mode command
can be used in the body of the text message
has to appear on a line by itself
starts with ~
~v use vi to edit or to view the mail message
When done use :wq to exit out of vi and return to mail send mode
~h edit the header of the mail message.
You will be prompted to edit the fields: To, Subject, cc, bcc
~r filename read (bring in) an existing text file into the current email message
filename can have a path
~m mesg_num mail (bring in) an existing email into the current email message
mesg_num is the number of the existing email in the receive mode
mail Receive Mode: Check for Mail
To start: mail
Without an argument, mail will be in receive mode
You will get a message no mail for yourID or
You will see a receive mail header, with fields: status message_num senderID date size subject
The symbol > in front of one of the messages indicates it is the current message
status: N for new, U for unread, blank for already read
message_num : a number, the numbers are in the order that the mail was received
senderID : email address of the person who sent the mail
date : the time and date received
size : number of lines / characters
subject : what the sender put in the subject field
Following the header, you will get the prompt &, this means mail is ready for the mail receive mode commands.
mail Receive Mode: Message Number
The receive mode commands can optionally accept a message number
If no message number is given, the command applies only to the current message
If there is a message number, it can follow the command immediately or with 1 or more space in between
How to use a message number:
8 command will apply to message 8
1,8,6 command will apply to messages 1,8,6
2-5 command will apply to messages 2 to 5, inclusive
$ command will apply to last message
* command will apply to all messages
mail Receive Mode: Commands
Receive mode commands (the [ ] indicates optional field):
To read a message: [message_num] <enter key>
The message will appear on screen and end with the & prompt
To see the mail header : h
The mail header shows all messages and their status
To delete: d [message_num]
To undo a delete: u [message_num]
- Can undo as many deleted messages as you have deleted in the session
To reply to sender only: R [message_num]
To reply to all r [message_num]
Both reply commands will take you to send mode, where you can type your reply
When you send the reply and get out of send mode, you’ll be back in the current receive mode
To bring the original mail into your reply email, use ~m in your reply to bring it in
To forward mail: m email_addr
This takes you to send mode
Then use the ~m command of send mode to bring in the message you want to forward
You can add any extra message of your own before send
When you send the forwarded message, you’ll get out of send mode and be back in receive mode
mail Receive Mode: Save Mail
To save and email to a mail folder:
s [msg_num] folder_name
A mail folder is a text file created by mail when you save a mail message
If the folder_name is new, the new text file is created
If folder_name already exists, mail will append the mail message to the text file
This text file can be opened by any utility that can open a text file, but it can also conveniently be read by mail itself
To use mail to read this mail folder:
mail –f folder_name
The option –f is for file
Each mail message in the file is displayed like in the mail receive mode
This provides a convenient way for you to sort your email into separate folders and view it with mail
mail Receive Mode: Exit
To exit out of mail: x
When you exit, mail will act as if you had not opened the current mail session
Messages with status N will still be N
Messages with status U will still be U
Messages that are deleted will be restored
Messages that are read will keep their status (U or N)
However, messages that are sent or saved in a folder will still have been sent or saved in a folder
mail Receive Mode: Quit
To quit out of mail: q
When you quit, mail keeps track of the status of the current session
Therefore messages will have updated status
Messages that are read: go into a folder called mbox, created by mail automatically in your home directory
To see these messages, use mail to open the folder mbox:
mail –f (with no argument)
Messages that are not read: stay in your inbox and marked with status U
Messages that are saved: go to the folder that you saved in
Messages that are deleted: gone
Topics:Communication with Other Users
Messaging with write and talk
write
talk
mesg
mail commands
send mode: How to send an email on linux system
receive mode: How to receive an email
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