$ZB contains a string specifying the input terminator for the last terminal READ. $ZB contains null and is not maintained for devices other than terminals. $ZB may contain any legal input terminator, such as <CR> (ASCII 13) or an escape sequence starting with <ESC> (ASCII 27), from zero (0) to 15 bytes in length. $ZB contains null for any READ terminated by a timeout or any fixed-length READ terminated by input reaching the maximum length.
$ZB contains the actual character string, not a sequence of numeric ASCII codes.
SET zb=$ZB FOR i=1:1:$L(zb) WRITE !,i,?5,$A(zb,i)
This displays the series of ASCII codes for the characters in $ZB.
$ZB refers to the last READ terminator of the current device. Therefore, exercise care in sequencing USE commands and references to $ZB.
GT.M does not permit the SET command to modify $ZB.
For more information on $ZB, refer to the "Input/Output Processing" chapter.