Availability:built-in
read_string(+Stream,
?Length, -String)Read at most Length characters from Stream and
return them in the string String. If Length is
unbound, Stream is read to the end and Length is
unified with the number of characters read. The number of bytes
read depends on the encoding of Stream (see section
2.18.1). This predicate may be used to read a sequence of bytes when
the stream is in octet encoding. See open/4
and set_stream/2
for controlling the encoding.