Rendering Markdown, Asciidoc and Friends automatically while Editing //at 15:41 //by abe

Partially because of Markdown being Github’s markup format of choice, I enjoy writing documents in simple markup formats more and more.

There’s though one common annoyance with these formats compared to writing plain HTML…

The Annoyance

They need to be rendered (i.e. more or less compiled) before you can view your outpourings rendered, e.g. in the web browser. So the workflow usually is:

1. Saving the current file in your favourite editor
2. Switch to terminal with commandline
3. Cursor up, Enter
4. Switch to your favourite web browser
5. Hit the reload button

Using a Specialized Editor with Live Preview

One choice would be to use a specific editor with live rendering. The one I know in Debian (from Wheezy on) is ReText (Debian package retext). It supports Markdown and reStructuredText.

But as with most simple GUI editors, I miss there many of the advanced editing commands possible with Emacs.

Using Emacs’ Markdown Mode

Then there is the Markdown Mode for Emacs (part of Debian’s emacs-goodies-el package), where you can get a “preview” by pressing C-c C-c p. But for some reason this takes several seconds, opens a new buffer and window with the rendered HTML code and then starts (hardcoded) Firefox (which is not my preferred web browser). And if you do that a second time without closing Firefox first, it won’t just reload the file but will open a new tab. You might think that just hitting reload should suffice. But no, the new tab has a different file name, so reload doesn’t help. Additionally it may not use my preferred Markdown implementation. Meh.

Well, I probably could fix all those issues with Markdown Mode, it’s only Emacs Lisp. Heck, the called command is even configurable. But fixing at least four issues to fix one workflow annoyance? Maybe some other time, but not as long there are other nice choices…

Using inotifywait to Render on Write

So everytime you save the currently edited file, you immediately want to rerender the same HTML file from it. This can be easily automated by using Linux’ inotify kernel subsystem which notices changes to the filesystem, and reports those to applications which ask for it.

One such tool is inotifywait which can either output all or just specific events, or just exit if the first requested event occurs. With the latter it’s easy to write a while loop on the commandline which regenerates a file after every write access. I use either Pandoc or Asciidoc for that since both generate full HTML pages including header and footer, but you can use that also with Markdown to render just the HTML body. Most browsers render it correctly anyway:

while inotifywait -q -e modify index.md; do pandoc -s -f markdown -t html -o index.html index.md; done
while inotifywait -q -e modify index.txt; do asciidoc index.txt; done
while inotifywait -q -e modify index.md; do markdown index.md > index.html; done

This solution is even editor- and build-system-agnostic (But not operating-system-agnostic.)

inotifywait is part of inotify-tools, a useful set of commandline tools to interface with inotify. They’re packaged in Debian as inotify-tools, too.

Using mdpress for Markdown plus Impress.js based Slides

The ruby-written mdpress is a special case of the previous case. It’s a commandline tool to convert Markdown into Impress.js based slide shows and it has an option named --automatic which causes it to keep running and automatically update the presentation as soon as changes are made to the Markdown file.

mdpress is not yet in Debian, but there’s an ITP for it and Impress.js itself recently entered Debian as libjs-impress. Nevertheless, two dependencies (highlight.js, ITP‘ed, ruby-launchy, ITP‘ed) are still missing in Debian.

Conkeror in the Debian NEW queue //at 22:57 //by abe

I already mentioned a few times in the blog that I’m working on a Debian package of the Conkeror web browser. And now, after a lot of fine-tuning (and I still further new ideas how to improve the package ;-) Conkeror is finally in the NEW queue and hopefully will hit unstable in a few days. (Update Thursday, 03-Jul-2008, 18:13 CEST: The package has been accepted by Jörg and should be included on most architectures in tonight’s updates.)

Those who could hardly await it can fetch Conkeror .debs from http://noone.org/debian/. The conkeror package itself is a non-architecture specific package (but needs xulrunner-1.9 to be available), and its small C-written helper program spawn-process-helper is available as package conkeror-spawn-process-helper for i386, amd64, sparc, alpha, powerpc, kfreebsd-i386 and kfreebsd-amd64. There are no backported packages for Etch available, though, since I don’t know of anyone yet, who has successfully backported xulrunner-1.9 to Etch.

Interestingly the interest in Conkeror seems to have risen in the Debian community independently of its Debian packaging. Luca Capello, who sponsored the upload of my Conkeror package, pointed me to two blog post on Planet Debian, written by people being fed up with Firefox 3 already and are looking for a more lean, but still Gecko based web browser: Decklin Foster is fed up with Firefox’ -eh- Iceweasel’s arrogance and MJ Ray is fed up with Firefox 3 and its SSL problems.

Since my previously favourited Gecko based web browser Kazehakase never became really stable but instead became slow and leaking memory (and therefore not much better than Firefox 2), I can imagine that it’s no more an candidate for people seaking for a lean and fast web browser.

Conkeror has some “strange” concepts of which the primary one is that it looks and feels like Emacs:

• The current location is shown in a status bar below the website, where Emacs usually shows buffer names. All input, even entering new URLs to go to, is done via the mini-buffer, an input line below the status bar.

• Instead of tabs it uses Emacs’ concept of buffers. So no tab bar clutter and though easy access to all currently open pages.

• It has no buttons, menu-bar or such. And except the status bar and mini-buffer, it uses the whole size of the window for the displayed web page. This is the main reason why I prefer Conkeror on the 7” EeePC: I don’t want to waste any pixels for buttons or menu bars and still have a fully functional web browser.

• It of course has Emacs alike keybindings (with a slight touch of Lynx). While this may seem awkward for the vi world (Hey, they have the vimperator^*, also in Debian since a few days!), as an Emacs user you just have to remember that you web browser now also expects to be treated like an Emacs. It just works:

  C-x C-c

  Exit Emacs -eh- Conkeror

  C-x C-f

  Open File -eh- web page in new buffer

  C-x C-b

  Change to some other tab -eh- buffer

  C-x C-v

  Replace web page in this buffer and use the current URL as start for entering the new one

  C-x 5 2

  Open new frame -eh- window

  C-x 5 0

  Close current frame -eh- window

  C-x k

  Close tab, -eh- kill buffer

  C-h i

  Documentation

  C-s

  Incremental search forward

  C-r

  Incremental search backward

  C-g

  Stop

  l

  Go back (Think info-mode)

  g

  Go to (Open web page in this buffer)

  (Hehe, I like the faces of vi users having read these keybindings and now wondering how to remember them. SCNR. Well, sometimes vi key bindings are a mystery to me, too. :-)

  There are of course many more and nearly all are the same as in Emacs, even the universal argument C-u and the M-x command-line are there. E.g. C-u g lets you open a web page in a new buffer, too.

• Conkeror also has very promising concept for following and copying links with the keyboard only. Opera is very inefficient here since you have to jump from link to link to get to the one you want. In Conkeror you just press f for following or c for copying links and then all links on the currently shown part of the page show a small number attached to it. Then you just enter the number (and additionally press enter if the number is ambigous) and the link is either opened or copied to the clipboard.

  A funny anecdote about how this concept grew over the time: Early versions of Conkeror (back in the days when it just was a Firefox externsion as vimperator) numbered all links on the page, not only the visible ones. On large pages with many links or buttons (e.g. my blog ;-), this took minutes to complete. The idea to just number the visible links is so simple and important – but someone first needed to have it. :-)

Footnotes

*) I just noticed that there is now also muttator, making Thunderbird look and behave like vim (and probably also mutt), too. Wonder into which e-mail client the Emacs community will convert Thunderbird. GNUS? RMAIL? VM? Wanderslust? What will it be called? Wunderbird? Thunderslust? (SCNRE ;-)

Emacs Macros: Repeat on Steroids //at 16:06 //by abe

vi users have their . (dot) redo command for repeating the last command. The article Repeating Commands in Emacs in Mickey Petersen’s blog Mastering Emacs explained Emacs’ equivalent for that, namely the command repeat, by default bound to C-x z.

I though seldomly use it as I mostly have to repeat a chain of commands. What I use are so called Keyboard Macros.

For example for the CVE-2011-3192 vulnerability in Apache I added a line like Include /etc/apache2/sites-common/CVE-2011-3192.conf to all VirtualHosts.

So I started Emacs with all the relevant files: grep CVE-2011-3192 -l /etc/apache2/sites-available/*[^~] | xargs emacs &

To remove those “Include” lines again M-x flush-lines is probably the easiest way in Emacs. So for every file I had to call flush-lines with always the same parameter, save the buffer and then close the file or — in Emacsish — “kill” the buffer.

So while working on the first file I recorded my doing as a keyboard macro:

C-x (

Start recording

M-x flush-lines<Enter>CVE-2011-3192<Enter>

flush all lines which contain the string “CVE-2011-3192”

C-x C-s

save the current buffer

C-x C-k<Enter>

kill the current buffer, i.e. close the file

C-x )

Stop recording

Then I just had to call the saved macro with C-x e. It flushed all lines, saved the changes and switched to the next remaining file by closing the current file with three key-strokes. And to make it even easier, from the second occasion on I only had to press e to call the macro directly again. So I just pressed e for a bunch of time and had all files edited. (In this case I used git diff afterwards to check that I didn’t wreck anything by half-automating my editing. :-)

Of course there are other ways to do this, too, e.g. use sed or so, but I still think it’s a neat example for showing the power of keyboard macros in Emacs. More things you can do with Emacs Keyboard Macros are described in the EmacsWiki entry Keyboard Macros.

And if you still miss vi’s . command in Emacs, you can use the dot-mode, an Emacs mode currently maintained by Robert Wyrick which more or less automatically defines keyboard macros and lets you call them with C-..

Notes from the Emacs Skills Exchange Session at DebConf11 //at 12:29 //by abe

Thomas Koch asked at DebConf 11 for a Skills Exchange session about Emacs.

As nobody stepped up for that session for quite some time, I did. But I knew just the answers to half of his questions by mind, so I left the remainder for someone else. Luckily Kan-Ru Chen and Sebastian Tennant stepped up for most of the remainder.

We had a quite full meeting room and the notes that Kan-Ru and me prepared in Gobby (debian package) got collaboratively extended from being a braindump and guide what to talk about to a quite helpful, but compact and dense Emacs introduction.

I’ll probably use this as a base for an Emacs tutorial or workshop at some European FLOSS events, but I wouldn’t be able to have such a good and comprehensive base for that without that Skills Exchange session.

So thanks to all who contributed!

Update, 02:31: There also seem to exist an Emacs Lisp implementation of the Obby protocol called Ebby, but it doesn’t seem to support the 0.5 version of Gobby, only version 0.3.

SuSE sucks! //at 05:44 //by abe

Since SuSE closes the security support two years after release and the recent KDE JavaShit remote code execution hole wasn’t patched as fast as I would have expected it (the patch came out after the upgrade I’m writing about here) in the SuSE 9.0 which was installed on my 2.66 GHz AMD desktop at work (it started as in 2002 as a SuSE 7.3 on a 400 MHz box and has been upgraded since then to 8.0, 8.2 and 9.0 IIRC), I decided, it’s now really time to upgrade to SuSE 10.0. (Although 10.1 will be out soon, I just don’t want to wait for it.) And since my boss only wants SuSE boxes and neither Debian (which I would prefer) nor Gentoo (which a colleague prefers), I couldn’t simply install Sarge on this box although I would have chosen that option if it would have been available.

Since my former SuSE experiences told me that this would mean a lot of trouble, I took notes from the beginning, once for the blog and once for my boss to show him, that most trouble doesn’t come from me being a power user used to being allowed to touch any config file (like I am on Debian).

Preparations

So I begin with the preparations: Starting the 400 MHz Debian Woody box on my desktop (whose operating system is more than a year older than SuSE 9.0 and still has security support, yeah!) I usually need to build custom Debian packages for customers. There I could chat in IRC and took notes while trying to upgrade and get the whole thing working again.

When everything was ready, I put the SuSE DVD in — just to notice, that it’s just a CD-ROM. So I put the SuSE 10.0 CD1 in the CD-ROM drive and typed “sudo shutdown -r now” in the shell. The box starts shutting down and tells me:

Please stand by while rebooting the system…

But it didn’t reboot. I waited for several minutes, nothing happend. Well, seems as if the SuSE upgrade already starts as I expect it to end: Horrible.

Read more…

Still happy with the ASUS EeePC 701 //at 16:02 //by abe

Recently Eric asked on the LUG Vorarlberg mailing list about netbook experience. I wrote a lengthy reply summarizing my experiences with the ASUS EeePC 701. And I thought this is something I probably should share with more people than only one LUG:

I ordered an ASUS EeePC 701 (4G) with US keyboard layout at digitec in Spring 2008, got it approximately one month later and posted a first resumé after one month in my blog.

I’m still very happy with the EeePC 701, despite two commonly mentioned drawbacks (the small screen resolution and the small SSD – which I both don’t see as real problems) and some other minor issues.

What matters

• Very robust and compact case. And thanks to a small fan being the only moving part inside, the EeePC 701 is also very robust against mobile use.
• Very pleasing always-in-my-daypack size (despite the 7" screen it’s the typical 9" netbook size) and easily held with one hand.
• Black. No glossy display. Neither clear varnish nor piano laquer. Short: No bath room tile. Textured surface, small scratches don’t stick out and don’t matter.
• Debian (previously Lenny, now Sid) runs fine on it, even the webcam works out-of-the-box.
• Despite all those neat features, it was fscking cheap at that time. And it was available without Windows.

Nice to have

• There’s power on the USB sockets even if the EeePC is turned off but the power supply is plugged in.
• The speakers are impressingly good and loud for their size. (But my demands with regards to audio are probably not too high, so audiophiles shouldn’t run to ebay because of this. ;-)
• It has three external USB sockets.

What doesn’t matter

• The small 7" 800×480 screen: I like small fonts and do most things inside a terminal anyway. And even with 800×480, those terminals are still much bigger than 80×25 characters. Only some applications and webpages have no heart for small screens.
• The small disk size: Quite a lot of programs fit on 4 GB of disk space. Additionally I use tmpfs a lot. And music and video files are either on a external 500 GB Western Digital 2.5" “My Passport” disk (which I need quite seldomly) or much more come via sshfs and IPv6 from my home server anyway. :-)
• The small keyboard: I just don’t have any problems with the size or layout (right shift right of the cursor up key, etc.) of the keyboard. Well, maybe except that any standard sized keyboard feels extremely large after having used the EeePC exclusively for some weeks. ;-)
• The to 630 MHz underclocked 900 MHz Intel Celeron: It’s enough for most of the things I do with the EeePC. Also the original 512 MB RAM are somehow ok, but for using tmpfs, but no swap space at all, 1 GB or 2 GB are surely the better choice.
• A battery runtime of 2.5h to 3h is fine for me.

What’s not so nice

• The “n” key needs to be pressed slighty stronger than other keys, otherwise no “n” appears. So if one of my texts in average misses more “n” than other letters, I typed it on the EeePC. ;-)
• Home, End, Page-Up, and Page-Down need the Fn key. This means that these keys can only be used with two hands (or one very big hand and I have quite small hands). This is usually no problem and you get used to it. It’s just annoying if you hold the EeePC with one hand and try to type with the other.
• What looks like a single mouse button is a seesaw and therefore two mouse buttons below one button. This makes it quite hard to press both at the same time, e.g. for emulating a middle mouse button press. It usually works in about half of all cases I tried it. My solution was to bind some key combination to emulate a middle mouse button in my window manager, ratpoison:

  bind y ratclick 2

  And that mouse button bar already fell off two times.
• The battery reports only in 10% steps, and reporting in percentage instead of mAh is an ACPI standard violation because reporting in percentage is only allowed for non-rechargable batteries. It also doesn’t report any charging and discharging rates. But in the meanwhile nearly all battery meter can cope with these hardware bugs. This was quite a problem in the early days.
• Now, after approximately 1.5 years, the battery slowly fritzes: When charging there are often only seconds between 10% and 40%. Rigorously using up all power of the battery helped a little bit. Looks like some kind of memory effect althought the battery is labeled Li-Ion and not Ni-MH and Li-Ion batteries are said to have no memory effect.
• The SD card reader only works fine if you once completed the setup of the original firmware or set the corresponding BIOS switch appropriately. No idea why.

Similar models

Technically, most of this also counts for the EeePC 900SD (not 901) which only differs in screen, resolution and disk size as well as CPU, but not on the the case. So same size, same robustness, same battery, same mainboard, bigger screen, resolution, disk and faster CPU. (The 901 has a different CPU, a different battery, and a different, glossy and partially chromed case.) See Wikipedia for the technical specifications of all EeePC models.

ASUS’ only big FAILure

Stopping to sell most EeePCs with Linux and cowardly teaming up with Microsoft after having shown big courage to come out with a Linux only netbook. Well, you probably already know, but it’s better without Windows…

So basically you no more get these really neat netbooks from ASUS anymore and you get nearly no netbooks with Linux from ASUS in the stores anymore. It’s a shame.

Would I buy it again?

Sure.

Well, maybe I would also buy the 900SD, 900AX (replacing the harddisk with an SSD) or 702 (8G) instead of the 701, but basically they’re very similar. See Wikipedia for the differences between these EeePC models. And of course I still prefer the versions without Windows.

But despite the low price, the EeePC 701 is surprisingly robust and still works as on the first day (ok, except battery, the mouse button bar and the “n” key ;-), so I recently bought a second power supply (only white ones were available *grrrr*) and ordered a bigger third party battery plus an adapter to load the battery directly from the (second) power supply without EeePC inbetween.

What desktop do I use on the EeePC?

None.

I use ratpoison as window manager, uxterm, urxvt, and yeahconsole as terminal emulators (running zsh with grml based .zshrc even as root’s login shell :-), wicd-curses as network manager and xmobar (previously dzen2) with i3status as text-only panel. Installed editors are GNU Emacs 23, GNU Zile and nvi. (No vim. :-)

And of course a netbook wouldn’t be a netbook if it wouldn’t have a lot of network applications installed. For me the most important ones are: ssh, scp, autossh, sshfs, miredo, conkeror, git, hg, and rsync.

Bath Tub, Rubber Keyboard, Ratpoison and Opera //at 18:24 //by abe

I recently noticed that a very good way to safely read webcomics in the bath tub is an old laptop with a big screen (e.g. a IBM ThinkPad A-series like my 15” A31 which has a nice 1400×1050 resolution), a water proof keyboard, the screen-alike, keyboard only driven (hence the name) window manager ratpoison (other keyboard driven window managers like wmii or awesome probably will do as well as ratpoison) and a good keyboard driven web browser which can bind or by default has bound a key to follow <link rel="next" ... /> tags.

Like Opera. Opera has bound the space bar to scroll one page down and if you reach the bottom of the page to go to the next page as labeled in the link tag. Additionally the full screen mode is helpful, too.

Or the dream browser of all Emacs addicts, Conkeror, which has bound the function browser-follow-next to ]]. (Conkeror packages will hit Debian Experimental quite soon.)

Or the GNOME feed reader Liferea which has bound Ctrl-Space by default to scroll down the content by one page and if you reach the bottom of the content go to the next unread item.

With that equipment I can read my favourite web comics like Questionable Content (whose content seldomly is questionable :-) or Ozy and Millie (Think of a mixture of Calvin & Hobbes, Peanuts and Kevin & Kell) in the bath tub without drying my hands before reading the next comic or fearing water or health damage by the combination of water and computer. I just press one or two keys on the keyboard floating over my lap and have a good time.

BTW: I’ve got a blue, non-branded one (packaging reveals it as “AirTouch Keyboard”, probably manufactured by SanChuan Electronics, China) with swiss-german layout from ARP Datacom (whose website offers no permanent links and insists on session cookies *puke*), but those from Keysonic or from ROCK seem to be very similar — nowadays they are also available in illuminated, miscellaneous colors and wireless, but only IP65, probably because of the necessarily accessible battery compartment.

But this kind of having fun still has optimisation potential: non-flexibel water-proof keyboard (IP67 recommended, so those IP66 keyboards and mice recently posted at UF LOTD are probably not tight enough), flat screen mounted above the bath tub, etc. ;-) Or maybe a completely water proof laptop if such thing exists — Does it?

One more note: In Debian Sid and Lenny recently a new tool called keynav has been added, which allows you to control the mouse quickly using the keyboard only. So with Sid or Lenny, I don’t even need an waterproof mouse or trackball if an application insists on mouse usage. ;-)