[ Stream I/O | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]

at_eof(+Stream)

Succeeds if the position of the pointer to stream Stream is at the end of file.
+Stream
Integer (stream number) or Atom (reserved or user-defined symbolic stream name).

Description

Used to test if the position of the pointer to stream Stream is at the end of file.

Stream can be a symbolic stream name or a physical stream number.

Fail Conditions

Fails if Stream is a file with its pointer not at end of file.

Resatisfiable

No.

Exceptions

(4) instantiation fault
Stream is not instantiated.
(5) type error
Stream is instantiated, but not to an atom or an integer.
(192) illegal stream mode
Stream is an illegal stream mode.

Examples

Success:
      at_eof(null).

      [eclipse]: open(file1,write,s), at_eof(s),
      > write(s,hello), at(s,5), at_eof(s), close(s).
      yes.

Fail:

      [eclipse]: open(file1,write,s),write(s,hello), close(s),
      > open(file1,read,s), at_eof(s), close(s).
      no.

Error:
      at_eof(X).                  (Error 4).
      at_eof("s").                (Error 5).
      at_eof(not_a_stream).       (Error 192).

See Also

at / 2, seek / 2