1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2011-2020, VU University Amsterdam 7 All rights reserved. 8 9 Redistribution and use in source and binary forms, with or without 10 modification, are permitted provided that the following conditions 11 are met: 12 13 1. Redistributions of source code must retain the above copyright 14 notice, this list of conditions and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in 18 the documentation and/or other materials provided with the 19 distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 POSSIBILITY OF SUCH DAMAGE. 33*/ 34 35:- module(http_files, 36 [ http_reply_from_files/3 % +Dir, +Options, +Request 37 ]). 38:- use_module(library(http/http_dispatch)). 39:- use_module(library(http/http_dirindex)). 40:- use_module(library(filesex)). 41:- use_module(library(lists)). 42:- use_module(library(option)). 43 44:- predicate_options(http_reply_from_files/3, 2, 45 [ indexes(list(atom)), 46 not_found(oneof([fail,404])), 47 pass_to(http_dispatch:http_reply_file/3, 2), 48 pass_to(http_dirindex:http_reply_dirindex/3, 2) 49 ]).
indexes to
locate an index file (see below) or uses http_reply_dirindex/3
to create a listing of the directory.
Options:
['index.html'].fail makes the handler fail silently. 404 make the
handler call http_404/2. Default is fail.
Note that this handler must be tagged as a prefix handler (see
http_handler/3 and module introduction). This also implies that
it is possible to override more specific locations in the
hierarchy using http_handler/3 with a longer path-specifier.
When using http_handler/3 to bind this predicate to an HTTP
location, make sure it is bound to a location that ends in a /.
When using http:location/3 to define symbolic names to HTTP
locations this is written as
http_handler(aliasname(.),
http_reply_from_files(srcdir, []),
[prefix]).
118http_reply_from_files(Dir, Options, Request) :- 119 ( memberchk(path_info(PathInfo), Request) 120 -> true 121 ; PathInfo = '' 122 ), 123 http_safe_file(PathInfo, []), 124 locate_file(Dir, PathInfo, Result, ResultType, Options), 125 !, 126 reply(ResultType, Result, Options, Request). 127http_reply_from_files(_Dir, Options, Request) :- 128 option(not_found(404), Options), 129 http_404(Options, Request). 130 131reply(file, Path, Options, Request) :- 132 http_reply_file(Path, [unsafe(true)|Options], Request). 133reply(index, Path, Options, Request) :- 134 http_reply_dirindex(Path, [unsafe(true)|Options], Request). 135reply(redirect, _, _, Request) :- 136 memberchk(path(Path), Request), 137 atom_concat(Path, /, NewLocation), 138 http_redirect(moved_temporary, NewLocation, Request). 139 140locate_file(Dir, PathInfo, Result, ResultType, Options) :- 141 absolute_file_name(Dir, DirPath, 142 [ file_type(directory), 143 access(read), 144 solutions(all) 145 ]), 146 directory_file_path(DirPath, PathInfo, Path), 147 ( exists_file(Path) 148 -> ResultType = file, 149 Result = Path 150 ; exists_directory(Path), 151 ( sub_atom(Path, _, _, 0, /) 152 -> ( option(indexes(Indexes), Options, ['index.html']), 153 member(Index, Indexes), 154 directory_file_path(Path, Index, IndexFile), 155 exists_file(IndexFile) 156 -> Result = IndexFile, 157 ResultType = file 158 ; Result = Path, 159 ResultType = index 160 ) 161 ; ResultType = redirect 162 ) 163 )
Serve plain files from a hierarchy
Although the SWI-Prolog Web Server is intended to serve documents that are computed dynamically, serving plain files is sometimes necessary. This small module combines the functionality of http_reply_file/3 and http_reply_dirindex/3 to act as a simple web-server. Such a server can be created using the following code sample, which starts a server at port 8080 that serves files from the current directory ('.'). Note that the handler needs a
prefixoption to specify that it must handle all paths that begin with the registed location of the handler.:- use_module(library(http/http_server)). :- use_module(library(http/http_files)). :- http_handler(root(.), http_reply_from_files('.', []), [prefix]). :- initialization(http_server([port(8080)]), main).