Contains information about the current terminal I/O device.
contains information about the current I/O device.
For a terminal device that is a Terminal, $ZIO
contains the string TRM:
. If the current terminal device is connected remotely, $ZIO
contains information about the remote connection.
For a terminal device connected through TELNET, $ZIO
contains the following: host
If the current device is not a terminal:
If a file, $ZIO
contains the full canonical pathname of the file.
If not a file, $ZIO
contains the null string.
The following example returns the current device information:
SET x=$CASE($ZIO,"TRM:":"a terminal",
"":"neither terminal nor file")
WRITE "The current device is ",x
This special variable cannot be modified using the SET
command. Attempting to do so results in a <SYNTAX> error.