Muli Ben-Yehuda's journal

Amir has merged the FreeBSD port to syscalltrack HEAD. HEAD now has support for Linux, FreeBSD, NetBSD and OpenBSD! cool beans.

Yesterday, Amir implemented support for ‘fullpath()’ and ‘fdpath()’ in the filter format. This is a feature our users (all two of them ;-)) have been asking for a long time. It allows the user to match against the full path of a file, or the full path of a file descriptor. Now you can have a rule that catches every read of ‘/etc/passwd’, without catching ‘open’ first and noting the file descriptor. Of course, this is NOT SECURE, since another thread could come in and modify the syscall parameters after we check them and before the kernel acts on them, but syscalltrack is a debugging, not security, tool.

I had a nice idea today during a discussion with Amir and choo on syscalltrack-hackers, to unify the filtering and logging syntax and mechanisms. The benefits are obvious, consistent configuration syntax and less complex kernel code, because the logging format is currently parsed completely in kernel, unlike the filter format. The only disadvantage is breaking configuration file backward compatibility. I think it’s something we can still afford to do, at this stage of development. I might even take a stab at implementing it later tonight, after (during ;-)) Hamakor‘s yearly meeting. It will be a nice refresher from the weekend’s elisp hacking.

It’s days like these that make me appreciate free software. Whenever I
would post a blog entry with HTML’s ‘pre’ stanzas in it to
livejournal via ljupdate, the
entry would appear horribly mangled (exhibit
1). That in itself is not too bad, since I could go immediately to
the livejournal website and edit it to display properly, but when the
entry got syndicated on kerneltrap, it would make the
page impossbile to view. Unacceptable – exhibit 2.

So I dug into the ljupdate source code to figure out what was going
on. It turns out that ljupdate would munge the text in order to
prepare it for livejournal’s incoming filters, which would demunge it
into proper HTML. Unfortunately, the munging would destroy ‘pre’
stanzas, rendering them all on one long line.

After ascertaining that this was the problem, I set out to fix
it. First I tried to get ljupdate to not munge ‘pre’ stanzas, but
then, after reading this
post, I decided to implement an ‘HTML mode’ flag. A few hours
later and several tens of test posts later, it works.

all
on
different
lines!

ljupdate-allow-the-user-to-mark-post-as-html-A1 is the ljupdate
fix. Now to integrate with ljablog.el…

Rewrote ljablog.el’s main loop to be more lispish in nature. Sexy!

 
(defun ljablog-post () 
  "Post a ljablog entry to both livejournal and advogato."  
  (interactive) 
  (let 
    ((blogs 
      '((lj-compose lj-post) 
        (advogato-start-post advogato-save-post)))) 
    (progn 
      (mark-whole-buffer) 
      (copy-region-as-kill (point-min) (point-max)) 
      (mapcar 
        (lambda (x) 
          (funcall (car x)) 
          (end-of-buffer) 
          (yank) 
          (if ljablog-debug-do-post 
            (funcall (cadr x)))) 
    blogs)))) 

I decided to start posting blog entries to both livejournal and advogato. Since I post to both via The One True Editor anyway, it seemed only natural to write an elisp mode to post to both from. A few hours later, ljablog.el made its first appearance. Horribly hacky, but hey, if you’re reading this, it Works For Me…

testing unified blogging to advogato and livejournal via blog.el

advogato.el/advogato-el-let-user-specify-mozilla-profile-name-1.2-A1, a patch to advogato.el to allow the user to set his mozilla profile name. advogato.el uses the cookies file in the mozilla profile to dig up the advogato cookie. Without this patch, it fails if the user has a .mozilla profile but the profile name is neither the login name nor ‘default’. Example use:

 
;; posting to advogato 
(load-file "/home/muli/src/elisp/advogato.el") 
(defun advo-compose () 
  (interactive) 
  (advogato-start-post)) 
(setq advogato-mozilla-profile-name "whatever") 

I have to admit, I didn’t vote for this logo. But the more I look at
it, the more it grows on me. Good job, Alon!

Amir S. has been busy hacking on syscalltrack, including porting it to all of FreeBSD, NetBSD and OpenBSD. Awesome! He wants to make a new test release tomorrow (a year to the day since our last release). Watch this space…

I added a couple of syndicated feeds to livejournal in the last few days. The first is planetdebian, the collection of blogs of Debian developers, users and hangers-on (that would be me). The second is sikritinfo, the blog of Itamar Shtull-Trauring. Enjoy!

I like emacs’s mode bar to be choke full of information. To that end, I have it display for example the battery status, and also the current date and time. By default (XEmacs 21.4.14), when showing the date and time, it also shows the “you have mail” icon. But since I don’t read mail on the laptop, here’s how to get rid of it:

 
;; prepare to show current time 
(defun prepare-and-display-time() 
  ;; no mail icon - I don't read mail on this box 
  (setq display-time-form-list '(date time load)) 
  ;; do show the day and date 
  (setq display-time-day-and-date t) 
  ;; turn it on 
  (display-time))

;; turn it on 
(prepare-and-display-time) 

What is up with Linux Journal? as soon as I cancel my subscription, they start having quality articles!

The Feb 2004 issue has a nice motivational piece on the LinuxBIOS project. Unfortunately, it doesn’t seem to be available on the web.