You can generate the value of a variable for a .set or .bset command
by sending a command to the server's command interpreter. To use a
command within the dot command, enclose the command in backtick characters.
For example, the command:
.set env SetupGroup "PerlVer=`perl --version`"
sets the variable PerlVer to the output of the perl --version
command.
The variables can only store 256 characters; if more are assigned
to a variable, the value is truncated.
By default, the system assigns the entire output of a command in
backticks to the variable, but you can use range commands in brackets
to select which lines from the command output you want to assign to
your variable. The range numbers specify lines from the output using
a 0-index (the first line is numbered zero, the second 1, etc.). In
the following example,
.set env SetupGroup "WindowsIPinfo[0,5-8]=`ipconfig`"
the variable WindowsIPinfo receives the first and sixth through
ninth lines of the ipconfig command's output.
The following are all valid range modifiers, selecting single lines,
groups of lines or combinations:
[5]
[4-6]
[1,2,5,8-11]
The system combines lines without any separation; no spaces or
carriage returns are added.
Note: Do not mix the backtick form
and the standard assignment form of the command.