
read_string(+Delimiters, ?Length, -String)

   Reads a string from the input stream up to a delimiter or up to a specified length

Arguments
   Delimiters          String or atom.
   Length              Integer or variable.
   String              String or variable.

Type
   Character I/O

Description
   A string of characters is read from the input up to one character which
   occurs in the delimiter string Delimiters.  This character is also
   consumed, but does not appear in the string which is unified with
   String.
   
   Two symbolic Delimiters can be specified:



    end_of_line   a newline or carriage-return/newline sequence
    end_of_file   the end of the file/input

   End of file always acts like a delimiter.


   If Length is a variable, it is unified with the length of the string
   String.  If Length is an integer, the number of characters read from
   the input is limited by the Length.




Modes and Determinism
   read_string(+, +, -) is semidet
   read_string(+, -, -) is semidet

Fail Conditions
   There is nothing to read, i.e. the stream is at end_of_file

Exceptions
     4 --- Delimiters is not instantiated.
     5 --- Delimiters is not a string or atom.
     5 --- Length is not an atom or an integer.
     5 --- String is not an atom or a string.
     6 --- Delimiters is an atom but not a valid symbolic delimiter.
   190 --- End of file was encountered before reading any character.
   198 --- Trying to read even after the error 190 was raised.

Examples
      Equivalent to read_string(input, Delimiters, Length, String).  (see
   read_string/4 for details).





See Also
   read_string / 4, read_token / 2, read_token / 3, open / 3
