FILTERS/ PIPES AND COMMUNICATION

FILTERS/ PIPES AND COMMUNICATION

FILTERS AND PIPES

HEAD : It is used to display the top ten lines of file.

Syntax: $head<filename>

TAIL : This command is used to display the last ten lines of file.

Syntax: $tail<filename>

PAGE : This command shows the page by page a screenfull of information is displayed after which the page command displays a prompt and passes for the user to strike the enter key to continue scrolling.

Syntax: $ls –a\p

MORE : It also displays the file page by page .To continue scrolling with more command , press the space bar key.

Syntax: $more<filename>

GREP :This command is used to search and print the specified patterns from the file. Syntax: $grep [option] pattern <filename>

SORT : This command is used to sort the datas in some order.

Syntax: $sort<filename>

PIPE : It is a mechanism by which the output of one command can be channeled into the input of another command.

Syntax: $who | wc-l

TR :The tr filter is used to translate one set of characters from the standard inputs to another.

Syntax: $tr “[a-z]” “[A-Z]”

COMMUNICATION THROUGH UNIX COMMANDS

MESG

Description: The message command is used to give permission to other users to send message to your terminal.

Syntax: $mesg y

2.Command: WRITE

Description: This command is used to communicate with other users, who are logged in at the same time.

Syntax: $write <user name>

3.Command: WALL

Description: This command sends message to all users those who are logged in using the unix server.

Syntax: $wall <message>

4.Command: MAIL

Description: It refers to textual information, that can be transferred from one user to another

Syntax: $mail <user name>

5.Command: REPLY

Description: It is used to send reply to specified user.

Syntax: $reply<user name>