IFI Fossil Interface (IFI) for Emacs

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This manual (last modified Wed 8 Sep 2021 11:13:30 BST, base 21c953800f9) documents IFI Fossil Interface (IFI) version 0.1; part of its pre-alpha development phase.


Getting started:  
IFI buffers:  
Primary features:  
Design features:  
GNU Free Documentation License:  

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1 Introduction

Fossil is a distributed software configuration management (SCM) system with built-in HTTP server and web interface.

IFI provides two facilities for working with Fossil in Emacs; an enhanced shell buffer (see *Fossil shell* buffers) employing Fossil’s built-in shell, and a checkouts buffer (see The *Fossil checkouts* buffer) providing an overview of the current state of all Fossil checkout directories.

The enhanced shell facility may be loaded and used independently of the checkouts buffer facility, but the reverse is not possible. The checkouts buffer is dependent on one or more enhanced shells for carrying out Fossil commands. This is by design (see Design features).

IFI does not interfere with, and does not replace, Emacs’ generic version control interface VC (see (emacs)Version Control), when Venkat Iyer’s Fossil backend is installed:


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2 Getting started

Obtaining IFI:  
Staying informed:  

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2.1 Obtaining IFI

Not surprisingly, IFI’s development home is a Fossil repository known as ‘HEmP’:


The copy of HEmP hosted at the above URL is known as ‘canonical HEmP’. There you will find instructions on how to clone the repository as a whole, as well as a link to the latest IFI release tarball.

N.B. HEmP includes mulitiple Emacs projects. If you decide to clone the repository, pay attention to the ‘Anonymous quick start’ instructions found in file home.md at the top level of branch trunk, or at the above URL.

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2.2 Installation

Installation is the same whether you clone HEmP or download and extract a release tarball (see Obtaining IFI). In either case, the directory containing IFI’s source files:


must be added to Emacs’ load-path before you issue the command:

 M-x load-library RET ifi-loaddefs RET

At this point, the two IFI entry point commands:

 M-x fossil-shell
 M-x fossil-checkouts

are available but the set of source files that define each command have not been loaded (see (elisp)Autoload). To load the source files and begin using IFI, simply issue one of the above two commands. (See *Fossil shell* buffers or see The *Fossil checkouts* buffer).

To make the two IFI entry point commands available at start-up , add the following line to your .emacs init file:

 (require 'ifi-loaddefs)

If you prefer to load all IFI source files at start-up (rather than on first use), add this line to your .emacs init file instead:

 (require 'ifi-ckout)

This is sufficient because, as described in the introduction (see Introduction), the checkouts buffer facility depends on the enhanced shell facility and will ensure the shell facility is loaded.

Finally, you may load only the source files required by the enhanced shell facility, and ensure the checkouts buffer facility is available when it is needed, by adding these two lines to your .emacs init file:

 (require 'ifi-shell)
 (require 'ifi-loaddefs) ; make `M-x fossil-checkouts' available

As always, the time it takes to load Emacs Lisp source files can be reduced by byte compiling them beforehand (see (elisp)Byte Compilation). Visit the directory containing the IFI source files in Dired and issue command C-u 0 M-x byte-recompile-directory RET. The position of point is unimportant. IFI should compile cleanly in GNU Emacs version >= 26.3 and all later versions (see Compatibility).

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2.3 Documentation

This manual is included in release tarballs and is available online in the following formats:

HTML (Fossilized)


HTML (Standalone)




Plain text




N.B. The online editions of the manual document IFI’s development version and may differ substantially from the editions included in a release tarball, especially during its early development phases. (Current phase: pre-alpha).

The easiest way to browse the Info manual in Emacs (in the absence of an installation script) is to load Emacs library Dired Extra. (See (dired-x)Top). With Dired Extra loaded, simply visit the doc/ directory in Dired, position point on file ifi.info and type Shift-I.

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2.4 Compatibility

IFI development began in GNU Emacs 26.3 and is being continued in version 27.2. It should byte-compile cleanly, i.e. without warnings, in Emacs 26.3 and all later versions.

IFI has not been tested in earlier versions of GNU Emacs, nor on platforms other than GNU/Linux. Compilation bug reports are welcome. See Contributing.

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2.5 Staying informed

Stay informed about IFI development by signing up for email alerts at canonical HEmP:


You may choose between announcements, checkin (commit) alerts, forum posts, forum edits, ticket and wiki page alerts.

N.B. HEmP includes multiple Emacs projects. It is not possible to subscribe to IFI alerts only.

If desired, you may sign up anonymously, i.e. without a named user account.

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2.6 Contributing

Contributions to IFI development should be made at canonical HEmP. There you can post to the forum and open new tickets, anonymously if you prefer, i.e. without a named user account.

2.6.1 Canonical HEmP forum

The canonical HEmP forum is for general queries, feedback, policy deliberation, simple patches e.t.c.


N.B. HEmP includes multiple Emacs projects. The title of new forum posts discussing IFI development should therefore begin with IFI: . For example:

 IFI: Issue with multiple *Fossil shell* buffers

2.6.2 Patches

Creating an ordinary patch file with Fossil is simple:

 $ fossil diff > file.patch

When posting a patch to the forum, include in the title of your post the 10-digit artifact hash of the checkin/commit against which the patch was made. For example:

 IFI: Bugfix patch against 632729f34f

If you have cloned HEmP, the 10-digit artifact hash may be found either by examining the timeline (look for the *CURRENT* entry) or by issuing Fossil’s info command like so:

 $ fossil info current | grep ^hash: | cut -b 15-24

If you downloaded and extracted an IFI release tarball, the 10-digit artifact hash may be found in the VERSION file.

Note that it is generally best to upload a patch to a pastebin and include a link to the paste in the forum post, rather than including the patch in the forum post itself.

2.6.3 Fossil bundles

For more substantial contributions, the diff command may be inadequate since it cannnot record file renamings, file deletions, tag operations, checkin/commit messages e.t.c. In this case, it is better to clone HEmP, create and work on a development branch, e.g. ifi-fixes, and then send a Fossil bundle, which you would generate like so:

 $ fossil bundle export --branch ifi-fixes ifi-fixes.bundle

Internally, Fossil stores state information in SQLite database files, and a Fossil bundle is no different; it’s an SQLite database file. When attaching a Fossil bundle to an email, mime-type application/vnd.sqlite3 should therefore be used.

Enquire in the forum for an email address or use the Fossil administrator address fossil at domain sebyte.me).

N.B. For developers used to making pull or merge requests, no such facility exists in the Fossil ecosystem. Bundles are a powerful alternative.

2.6.4 Canonical HEmP checkin/commit access

The first step towards gaining checkin/commit access to canonical HEmP is to create a named user account and participate in IFI development using the forum.

To create a named user account, visit the canonical HEmP login page and click the button labelled ’Create A New Account’.

2.6.5 HEmP tickets

The canonical HEmP ticket facility is for formal bug reports and feature requests and should generally follow discussion in the forum.


N.B. HEmP includes multiple Emacs projects. The one line ticket summary should therefore begin with IFI: . For example:

 IFI:  Compilation error under Emacs 24.2

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3 IFI buffers

*Fossil shell* buffers:  The enhanced shell facility
The *Fossil checkouts* buffer:  The checkout directories overiew facility
The *Fossil timeline* buffer:  Pretty timelines
The *Fossil help* buffer:  Pretty help output

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3.1 *Fossil shell* buffers

Once IFI has been installed (see Installation), you may start a Fossil shell (and enter a *Fossil shell* buffer) by issuing command M-x fossil-shell RET. (In fact, M-x fos-sh RET is usually sufficient). This will start a fossil shell process in whichever directory is current when you issue the command. (See (emacs)File Names for a brief explanation of default-directory).

Let’s suppose that you are visiting your home directory in Dired when you issue the command M-x fossil-shell RET. Let’s suppose also that your home directory is not a Fossil checkout. The *Fossil shell* buffer will, not surprisingly, look like this:

 fossil (no repo)>

The shell is waiting for you to start issuing Fossil commands. For example:

 fossil (no repo)> info
 config-db:    /home/sebyte/.fossil
 fossil:       /home/sebyte/fossil/bin/fossil
 version:      2.17 [de417fb73c] 2021-08-06 07:58:18 UTC
 fossil (no repo)>

However, note the buffer’s header line in which a large red dot is followed by the abbreviated form of the current directory. Note also what happens when you type a comma immediately after the Fossil prompt; the minibuffer prompt reads Shortcut. (See IFI shortcuts). Let’s suppose a checkout of a newly initialised Fossil repository is found at ~/fossil/sandpit/foo and that you type cd RET and enter this checkout directory. The *Fossil shell* buffer would now look something like this:

 fossil (no repo)> info
 config-db:    /home/sebyte/.fossil
 fossil:       /home/sebyte/fossil/bin/fossil
 version:      2.17 [de417fb73c] 2021-08-06 07:58:18 UTC
 fossil (no repo)> [ cd ~/fossil/sandpit/foo/ ]
 fossil (unnamed)>

Behind the scenes, the previous fossil shell process has been killed, the current directory has changed and a new fossil shell process has been started. The (fake) shell command cd ~/fossil/sandpit/foo/ (delimited by brackets) records where in the sequence of commands the change of directory occurred.

Note also the changes to the buffer’s header line. Because the new fossil shell process is running within a Fossil checkout, the large red dot is now followed by the abbreviated form of the current directory, the name of the project, the name of the current branch, a count (in brackets) of how many checkins/commits the checkout is behind the branch head and, finally, the default remote sync URL of the Fossil repository to which the checkout belongs. (See IFI headlines).

Now let’s return to your home directory in Dired and issue the command M-x fossil-shell RET again. We find ourselves in the same *Fossil shell* buffer we were in before, but a second change of directory has taken place, returning us to where we were:

 fossil (no repo)> info
 config-db:    /home/sebyte/.fossil
 fossil:       /home/sebyte/fossil/bin/fossil
 version:      2.17 [de417fb73c] 2021-08-06 07:58:18 UTC
 fossil (no repo)> [ cd ~/fossil/sandpit/foo/ ]
 fossil (unnamed)> [ cd ~/ ]
 fossil (no repo)>

The *Fossil shell* buffer has been resued because user-cutomisable variable ifi-shell-use-multiple-buffers-p is bound to nil by default. Had you enabled use of multiple shell buffers before issuing the M-x fossil-shell RET command the second time, you would have found yourself in a new shell buffer, named *Fossil shell*<2>.

There’s no limit on how many shell buffers/processes may be alive at once but a directory may only have a single *Fossil shell* buffer associated with it at any one time.

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3.2 The *Fossil checkouts* buffer

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3.3 The *Fossil timeline* buffer

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3.4 The *Fossil help* buffer

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4 Primary features

Content goes here.

IFI headlines:  
IFI shortcuts:  

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4.1 IFI headlines

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4.2 IFI shortcuts

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5 Design features

Content goes here.

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Appendix A GNU Free Documentation License

Version 1.3, 3 November 2008
Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.

Everyone is permitted to copy and distribute verbatim copies
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    The purpose of this License is to make a manual, textbook, or other functional and useful document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

    This License is a kind of “copyleft”, which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

    We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.


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    If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.

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    You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

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    In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You must delete all sections Entitled “Endorsements.”


    You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

    You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.


    A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an “aggregate” if the copyright resulting from the compilation is not used to limit the legal rights of the compilation’s users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

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    Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

    If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.


    You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.

    However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

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ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

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If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with…Texts.” line with this:

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    being list.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.