AV-98/README.md

# OFFPUNK

A command-line, text-based and offline Gemini browser.

Focused on Gemini first but with some Gopher/web support available or projected, the goal of Offpunk is to be able to synchronise your content once (a day, a week, a month) and then browse it while staying disconnected.

Offpunk is a fork of the original [AV-98](https://tildegit.org/solderpunk/AV-98) by Solderpunk and was originally only called AV-98-offline as an experimental branch.

## Lightning introduction

You use the `go` command to visit a URL, e.g. `go gemini.circumlunar.space`. If xsel is installed, go will automatically fetch the URL from your clipboard.

Links in Gemini documents are assigned numerical indices.  Just type an index to
follow that link.

If a Gemini document is too long to fit on your screen, use the `less` command
to pipe it to the `less` pager.

Use `add` to add a capsule to your bookmarks and `bm` to show your bookmarks (which are stored in a file in you .config).

Use `offline` to only browse cached content and `online` to go back online.

Use the `help` command to learn about additional commands.

When launched with the "--sync" option, offpunk will run non-interactively and fetch content from your bookmarks and content tentatively accessed while offline. New content found in your bookmarks will be added to your tour.

With "--sync", one could specify a "--cache validity" in seconds. This option will not refresh content if a cache exists and is less than the specified amount of seconds old.

For example, running

`offpunk.py --sync --cache-validity 43200`

will refresh your bookmarks if those are at least 12h old.



## TODO

Known issues in the code:
* WONTFIX: Sync is slow if you have bookmarks with lot of links that change very often.
* FIXME0: Certificates error are not handled in --sync
* FIXME1: consider root file is always index.gmi
* FIXME2: offline web browser use os.system because it’s the only one that understands the ">> file.txt"

* TODO: Update blackbox to reflect cache hits.


This fork is an experiment by Ploum (=> gemini://rawtext.club/~ploum ) to add offline capabilities to AV-98, including a persistent "tour" option.

See how I browse Gemini offline => gemini://rawtext.club/~ploum/2021-12-17-offline-gemini.gmi

In AV-98, use the commands "online" and "offline" to switch between offline/online.
While offline, only content cached in .cache/av-98/ is accessed.

Use "av-98.py --sync" to build a cache containing your bookmarks and all links in your bookmarks. It might be quite slow the first time, be patient. You can also use the option "--cache-validity 3600" to only refresh cache which are at least 1h old (set the number of seconds according to your needs. If 0 or not set, cache-validity is considered as infinite).

Uncached ressources tentatively accessed offline will be accessed with the next --sync, including reload of already cached ressources. Already cached ressources might randomly be reloaded from time to time.

New ressources discovered in your bookmarks while --sync will be added to your tour. This means that if you have gemlogs in your bookmarks, any new posts in those will be added to your tour.

At the moment, caching only work for gemini:// ressources. gopher:// is not implemented and http(s):// ressources are sent to an "offline browser" (by default, None, nothing is done). It could be useful to, for example, send the http:// links to a text file in order to visit them while online.


## Dependencies

Offpunk has no "strict dependencies", i.e. it will run and work without anything
else beyond the Python standard library.  However, it will "opportunistically
import" a few other libraries if they are available to offer an improved
experience.

* The [ansiwrap library](https://pypi.org/project/ansiwrap/) may result in
  neater display of text which makes use of ANSI escape codes to control colour.
* The [cryptography library](https://pypi.org/project/cryptography/) will
  provide a better and slightly more secure experience when using the default
  TOFU certificate validation mode and is highly recommended.
* [Python magic](https://github.com/ahupp/python-magic/) is useful to determine the MIME type of cached object. If not present, the file extension will be used but some capsules provide wrong extension or no extension at all.

## Features

* TOFU or CA server certificate validation
* Extensive client certificate support if an `openssl` binary is available
* Ability to specify external handler programs for different MIME types
* Gopher proxy support (e.g. for use with
  [Agena](https://tildegit.org/solderpunk/agena))
* Advanced navigation tools like `tour` and `mark` (as per VF-1)
* Bookmarks
* IPv6 support
* Supports any character encoding recognised by Python

## RC files

You can use an RC file to automatically run any sequence of valid AV-98
commands upon start up.  This can be used to make settings controlled with the
`set` or `handler` commanders persistent.  You can also put a `go` command in
your RC file to visit a "homepage" automatically on startup, or to pre-prepare
a `tour` of your favourite Gemini sites.

The RC file should be called `av98rc`.  AV-98 will look for it first in
`~/.av98/` and second in `~/.config/av98/`.  Note that either directory might
already exist even if you haven't created it manually, as AV-98 will, if
necessary, create the directory itself the first time you save a bookmark (the
bookmark file is saved in the same location).  AV-98 will create
`~/.config/av98` only if `~/.config/` already exists on your system, otherwise
it will create `~/.av98/`.