* Navigation:: Fundamentals of Elpher navigation
* Bookmarks:: How to record and visit bookmarks
* Character encodings:: How Elpher handles different character encodings
+* Encrypted connections:: How and when TLS is enabled
* Customization:: How to customize various aspects of Elpher
* Index::
@end menu
page, with information on each of the default keyboard bindings.
From here you can move point between links (which may be menu items or
-inline URLs in text files) by using @key{TAB} and @kbd{Shift-TAB} keys,
+inline URLs in text files) by using @key{TAB} and @kbd{S-@key{TAB}},
as in Info. You can also jump directly to a menu item using @key{m}, or
use the standard Emacs or Evil motion and search commands to find your
way around. To open a link, press @key{RET}. (Where a mouse is
@menu
* Within-page navigation:: Moving about within a page
-* Between-page navigation:: Concepts and commands for moving between pages
+* Between-page navigation:: Commands for moving between pages
+* History and Caching:: Explanation of how Elpher represents history
@end menu
links and menu items.
@table @asis
-@item @kbd{tab} (@code{elpher-next-link})
+@item @key{TAB} (@code{elpher-next-link})
Move to the next link or menu item in the file.
-@item @kbd{<S-tab>}/@kbd{<backtab>} (@code{elpher-prev-link})
+@item @kbd{Shift-@key{TAB}}/@key{backtab} (@code{elpher-prev-link})
Move to the previous link or menu item in the file.
@item @kbd{m} (@code{elpher-jump})
@item @kbd{C} (@code{elpher-copy-current-url})
Add URL representing address of the current page to the kill-ring and
the system clipboard (if available).
-@end table
+@item @kbd{d} (@code{elpher-download})
+Download link at point and save the result as a file. The minibuffer
+will prompt for the name of the file to write, with the default name being
+the display string (if available) associated with the link.
+
+@item @kbd{D} (@code{elpher-download-current})
+This is similar to @code{elpher-downlowd}, but instead applies to the
+current page rather than a link.
+
+@item @kbd{w} (@code{elpher-view-raw})
+This displays the raw server response for the current page. While not
+useful for general browsing, it is useful for debugging incorrect rendering
+or out-of-spec server responses.
+@end table
-@node Between-page navigation, , Within-page navigation, Navigation
+@node Between-page navigation, History and Caching, Within-page navigation, Navigation
@section Between-page navigation
Moving to a different page can be accomplished in several ways,
@item
Following links to binary files (and image files on unsupported systems)
causes Elpher to prompt for a filename in which to save the content.
+
+@item
+Following links of type `h' with a selector having the `URL:' prefix, or
+non-gopher URLs in text files, will result in Elpher using an external
+programme to open the URL. This will be either the default system browser
+or, if the @code{elpher-open-urls-with-eww} customization variable is non-nil,
+Emacs' own EWW browser. (See @pxref{Customization}.)
+
@end itemize
-Once a text, menu or query response page is retrieved, its contents are
+Once a text, menu or query response page has been displayed, its contents are
cached for the duration of the Emacs session.
-@item @kbd{d} (@code{elpher-download})
-
@item @kbd{g} (@code{elpher-go})
+Open a particular page by specifying either its URL or directly entering
+a host, port and selector.
+
+Note that if a non-gopher protocol is used in the URL the result will be
+the same as following a URL link of the same type from a gopher menu.
@item @kbd{O} (@code{elpher-root-dir})
+Open the root page (empty selector) on the current host.
@item @kbd{u} (@code{elpher-back})
Return to the previous page, where ``previous'' means the page where the
page which was displayed immediately before the current page.
@end table
+
+@node History and Caching, , Between-page navigation, Navigation
+@section History and Caching
+
+The history and caching strategy in Elpher is extremely simple, but
+may be confusing without a good mental model of how it works. That
+is what this section attempts to provide.
+
+Essentially, @strong{every} time you navigate to a new page, either
+by clicking or pressing @key{RET} on a link, using @key{g} to jump
+to a new page by its address, or using @key{O} to open the root selector,
+the following two things occur:
+
+@enumerate
+@item
+the cursor position and content for the original page are recorded in an
+in-memory cache, and
+
+@item
+the original page is set as the ``parent'' of the new page.
+@end enumerate
+
+The only way to return to pages in this history is by using @key{u},
+which returns to the previous of the current page.
+@footnote{The addition of the new page to the history happens even if
+the new page is one that has been seen before. This is mostly the
+desired behaviour. However, opening an explicit ``back'' link provided
+by a gopher menu will also add a new entry to the history. Unless you
+haven't yet visited that menu, it's therefore better to use @key{u} to
+go back in this case.}
+
+One aspect that may seem peculiar is that Elpher lacks a corresponding ``next'' or
+``forward'' command. However, since Elpher caches the position of point,
+this will be automatically positioned on the link that was most recently followed
+from a given page. This means that, at least for links followed from menus
+and text files, the inverse of @key{u} is actually just @key{RET}.
+
+
@node Bookmarks, Character encodings, Navigation, Top
@chapter Bookmarks
-@node Character encodings, Customization, Bookmarks, Top
+Elpher has a very simple link bookmarking system involving the
+following commands:
+
+@table @asis
+@item @key{a} (@code{elpher-bookmark-link})
+Add a bookmark for the link at point. The minibuffer will prompt for
+a name for the bookmark, which defaults to the display string.
+
+@item @key{A} (@code{elpher-bookmark-current})
+Add a bookmark for the current page. The minibuffer will prompt for
+a name for the bookmark, defaulting to the display string associated
+with the link that was followed to reach the current page.
+
+@item @key{x} (@code{elpher-unbookmark-link})
+Immediately remove the bookmark (if one exists) to the link at point.
+
+@item @key{X} (@code{elpher-unbookmark-current})
+Immediately remove the bookmark (if one exists) to the current page.
+
+@item @key{B} (@code{elpher-bookmarks})
+Open a page displaying all current bookmarks. Note that this bookmark
+page is added to the history just as if you had opened it using a link.
+Thus to return to the previous page, use @kbd{u}. This also means
+that you can peruse the various bookmarks by visiting them in turn,
+using @kbd{u} to return to the bookmark page (where the position of point
+is cached), then moving to another bookmarked link and so on.
+@end table
+
+Bookmarks are stored as a s-exp in the file @file{elpher-bookmarks}
+in the user emacs directory (usually @file{~/.emacs.d/}).
+Any command which modifies the list of bookmarks immediately updates
+this file.
+
+@node Character encodings, Encrypted connections, Bookmarks, Top
@chapter Character encodings
-@node Customization, Index, Character encodings, Top
+Responses Elpher retrieves from servers are initially read as pure
+binary data. When the data is intended to be interpreted as textual (as
+determined by the type parameter of the gopher menu item or the gopher
+URL), this data needs to be @emph{decoded} into a sequence of
+characters. To do this properly requires knowledge of the encoding
+system used by whoever authored the document.
+
+Unfortunately gopher lacks a systematic way of acquiring this necessary
+information. Thus, the details of the coding system must be either inferred from the binary data,
+or must be specified by the user.
+
+By default, Elpher applies Emacs' built-in character encoding detection
+system to the full (undecoded) response data and uses this to attempt to
+convert it into a character string.
+(@xref{Recognize coding, Recognizing coding systems, ,emacs}.)
+While this can be okay, it is important to realise that its inference
+algorithm is extremely primitive and depends heavily on assumptions based
+on the language settings of your emacs system.
+
+The alternative is to explicitly set the coding system used for decoding
+using the following command:
+
+@table @asis
+@item @key{S} (@code{elpher-set-coding-system})
+Causes a elpher to prompt for a coding system to use for decoding
+future text. The @key{TAB} key can be used at this prompt to display a
+list of alternatives (which is extensive) and to autocomplete. An empty
+response will cause Elpher to return to its default autodetection
+behaviour.
+
+Note that changing the coding system only affects newly loaded text.
+Thus, if text has already been decoded using an incorrect system, you
+will need to select the correct coding and then reload the text using
+@key{R}.
+
+@end table
+
+@node Encrypted connections, Customization, Character encodings, Top
+@chapter Encrypted connections
+
+@node Customization, Index, Encrypted connections, Top
@chapter Customization
@node Index, , Customization, Top
The Lambda Lab / projects / elpher.git / blobdiff