Converts its first string argument to or from ZWRITE format (quoted graphics characters concatenated with $CHAR() representations of any non-graphic characters). The second integer expression controls the direction of conversion. The format of the $ZWRITE() function is:
$ZWRITE(expr[,intexpr])
The first argument specifies the string to convert to or from the ZWRITE format.
The second argument specifies the direction of conversion. When intexpr is not specified or evaluates to zero, $zwrite() converts the first argument to the ZWRITE format. When intexpr evaluates to a non-zero value, $ZWRITE() treats the first argument as being in ZWRITE format and attempts to convert it to a string with embedded non-graphic characters; if it is not in ZWRITE format, it returns an empty string.
Converting to zwrite format tends to produce a string that is longer than the input and therefore a $ZWRITE() result may exceed the maximum string length - the maximum input length that is guaranteed not to do so is a 116,510 byte string.
If all its arguments are literals, $ZWRITE() evaluates to a literal constant at compile time.
Note that non-graphic characters differ between M mode and UTF-8 mode.
Example:
GTM>set temp="X"_$char(10)_"X" ; $CHAR(10) is the linefeed character GTM>write temp X X GTM>write $zwrite(temp) "X"_$C(10)_"X" GTM>write $zwrite($zwrite(temp),1) X X GTM>
