Same as gets
Reads a line without terminating newline (as defined by the channel's -translation option) from the channel, channelId. If varName is omitted, the result is the string content of the line. If varName is provided, the line is written to that variable and the result is the length of line that was read (again, not including the terminator) or -1 if some sort of exceptional condition occurred (see chan blocked and chan eof).