Request terminal version string.
See terminal specific information below.
ESC]702;rxvt-unicode;Ⓝ;Ⓝ;ⓃESC\
With progname
set to the base name of the terminal executable (or it's invocations 0th argument) and v1
and v2
set to the first and third character in the version string. (i.e. for 9.21, v1
='9' and v2
='1')