SMAP(x [, /TRUNCATE, /ARRAY])
Maps x byte for byte into a string or string array. If
keyword /TRUNCATE is set, then truncates the string at the first
zero byte. If /TRUNCATE is not set but /ARRAY is, and if
in addition x is an array, then the result is a string
array, with each run along dimension zero transformed into one string in
the string array.