Convert the given file specification into an absolute path. Spec
is a term Alias(Relative) (e.g., (library(lists)
), a
relative filename or an absolute filename. The primary intention of this
predicate is to resolve files specified as Alias(Relative). This
predicate only returns non-directories, unless the option
file_type(directory)
is specified. Option is a
list of options to guide the conversion:
- extensions(ListOfExtensions)
- List of file extensions to try. Default is
’’
.
For each extension, absolute_file_name/3
will first add the extension and then verify the conditions imposed by
the other options. If the condition fails, the next extension on the
list is tried. Extensions may be specified both as .ext
or
plain ext
.
- relative_to(+FileOrDir)
- Resolve the path relative to the given directory or the directory
holding the given file. Without this option, paths are resolved relative
to the working directory (see working_directory/2)
or, if Spec is atomic and absolute_file_name/[2,3]
is executed in a directive, it uses the current source file as
reference.
- access(Mode)
- Imposes the condition access_file(File, Mode). Mode
is one of
read
, write
, append
,
execute
, exist
or none
. See also access_file/2.
- file_type(Type)
- Defines extensions. Current mapping:
txt
implies ['']
,
prolog
implies ['.pl',’’]
, executable
implies
['.so',’’]
and qlf
implies ['.qlf',’’]
.
The
Type directory
implies ['']
and
causes this predicate to generate (only) directories. The file type source
is an alias for prolog
for compatibility with SICStus
Prolog. See also prolog_file_type/2.
- file_errors(fail/error)
- If
error
(default), throw an existence_error
exception if the file cannot be found. If fail
, stay
silent.144Silent operation was the
default up to version 3.2.6.
- solutions(first/all)
- If
first
(default), the predicate leaves no choice point.
Otherwise a choice point will be left and backtracking may yield more
solutions.
- expand(Boolean)
- If
true
(default is false
) and Spec
is atomic, call expand_file_name/2
followed by member/2
on Spec before proceeding. This is a SWI-Prolog extension
intended to minimise porting effort after SWI-Prolog stopped expanding
environment variables and the ~
by default.
This option should be considered deprecated. In particular the use of wildcard
patterns such as *
should be avoided.
The Prolog flag verbose_file_search
can be set to true
to help debugging Prolog's search for
files.
This predicate is derived from Quintus Prolog. In Quintus Prolog, the
argument order was absolute_file_name(+Spec, +Options, -Path)
.
The argument order has been changed for compatibility with ISO and
SICStus. The Quintus argument order is still accepted.