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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
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