[ Operating System | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]

# exists(+File)

Succeeds if the file File (with absolute or relative pathname) exists. File can be a directory.

File
  Atom or string.

## Description

Used to see if the file File exists. File can be a directory. exists(File) is equivalent to get_file_info(File, mode, _).

### Modes and Determinism

- exists(+) is semidet

### Fail Conditions

Fails if the file File (with absolute or relative pathname) does not exist

### Exceptions

(4) instantiation fault
  File is not instantiated.
(5) type error
  File is neither an atom nor a string.

## Examples

    Success:
       [eclipse]: sh('ls myfile').
       myfile
       [eclipse]: exists(myfile).
       yes.

       [eclipse]: sh('ls /home/user/workdir').
       myfile
       [eclipse]: exists('/home/user/workdir').
       yes.

    Fail:
       [eclipse]: sh('ls nofile').
       nofile not found
       [eclipse]: exists(nofile).
       no.

    Error:
       exists(File).                          (Error 4).
       exists([file]).                        (Error 5).

## See Also

existing_file / 4, get_file_info / 3, sh / 1, system / 1, delete / 1, mkdir / 1