- Documentation
- Reference manual
- Built-in Predicates
- File System Interaction
- access_file/2
- exists_file/1
- file_directory_name/2
- file_base_name/2
- same_file/2
- exists_directory/1
- delete_file/1
- rename_file/2
- size_file/2
- time_file/2
- absolute_file_name/2
- absolute_file_name/3
- is_absolute_file_name/1
- file_name_extension/3
- directory_files/2
- expand_file_name/2
- prolog_to_os_filename/2
- read_link/3
- tmp_file/2
- tmp_file_stream/3
- make_directory/1
- delete_directory/1
- working_directory/2
- chdir/1
- File System Interaction
- Built-in Predicates
- Packages
- Reference manual
Availability:built-in
read, write, append, exist, none
or
execute. File may also be the name of a
directory. Fails silently otherwise. access_file(File, none)
simply succeeds without testing anything.
If Mode is write or append, this
predicate also succeeds if the file does not exist and the user has
write access to the directory of the specified location.
The bahaviour is backed up by the POSIX access() API. The Windows replacement (_waccess()) returns incorrect results because it does not consider ACLs (Access Control Lists). The Prolog flag win_file_access_check may be used to control the level of checking performed by Prolog. Please note that checking access never provides a guarantee that a subsequent open succeeds without errors due to inherent concurrency in file operations. It is generally more robust to try and open the file and handle possible exceptions. See open/4 and catch/3.