SCREEN COMMUNICATION

echo

- a command mainly used in shell scripts. Examples:
$ echo "Hello" # will print Hello on your screen
$ echo "Hello" > /dev/tty616 # will print Hello on someone elses screen (warning - can crash their screen!)
$ echo $DESTF10 # will print the value of the environment variable DESTF10
$ echo "\033Fdemo demo" # will echo demo to the status bar at the top of a wyse terminal
See also file shellscripts

read

- will read text from standard input and place it in the variable name specified. See file shellscripts

line

- waits until the user presses return before carrying on (writes what is typed to standard output). If used in a crontab/at job this instruction is ignored. See file shellscripts

talk 

- set up an interactive communication dialogue box between two users. Looks good but isn't really that useful.

write 

- writes a message to someone elses screen. Try typing 'write root' and then type a message, finishing with control-D.

banner 

- writes in huge letters across your screen! (max: 10 chars per word)

wall 

- send a message to all people on a system. Can only be executed by root (I think).

tput 

- tty type independent attribute setting (requires TERM variable and TERMCAP to be set). I only know these few bits:

• tput cnorm - turns the screen cursor on
• tput civis - turns the screen cursor off
• tput clear - clears the screen
• tput smso - turns all new text to bold
• tput rmso - turns all bold text off

tee (-a)

- command used in pipes to take a copy of the standard output. e.g.
$ ls | tee /tmp/x # would output ls normally and put a copy in /tmp/x. The option '-a' is used to append rather than replace files.