Emacs : eldoc mode and c-eldoc mode

eldoc mode as the name suggests provides documentation for Elisp files. This is a very useful and cool mode and shows the function signature in the mode-line when your cursor is on a particular function.  It also provides info on the variables. Check out the screen-shots below.

To start eldoc mode, add the following to your .emacs file

;;Turn on documentation in elisp mode
(add-hook 'emacs-lisp-mode-hook
          '(lambda ()
	     (turn-on-eldoc-mode)))

c-eldoc mode is eldoc mode for c. It displays the arguments of C functions while one is programming.

To add c-eldoc mode, get the latest c-eldoc.el, copy it in your load-path and then add then following to your .emacs file.

(add-hook 'c-mode-hook 'c-turn-on-eldoc-mode)

Emacs : PKGBUILD mode

Discovered an amazing major mode for Emacs a few days back to edit PKGBUILDs. Essentially based on shell mode with the following extra bindings specific to PKGBUILDs.

C-c C-a pkgbuild-tar
C-c C-b pkgbuild-makepkg
C-c C-e pkgbuild-etags
C-c RET pkgbuild-update-md5sums-line
C-c C-r pkgbuild-increase-release-tag
C-c C-u pkgbuild-browse-url

I especially like pkgbuild-update-md5sums-line – very useful.

It also has some other cool functions. Check it out here.

My fork of the same is available here.

Google Talk invisible mode in Pidgin

Setting the status invisible for a GTalk account has been a problem for a while now. Although there are third party plugins available, (like the one here) most of them do not seem to work. The basic reason of this is, although Google Talk is basically based on XMPP , it handles invisibility, away etc in a different way. And according to this ticket on the pidgin bug track, they don’t quite like it . After going through a bit of documentation mentioned here, I came up with the following xmpp console commands to make invisibilty work without a problem in pidgin for google talk.

1) This requires the XMPP console so start that plugin. It comes by default in Pidgin and can be enabled via Tools->Plugins.

2) Start the XMPP console. Tools -> XMPP Console.

For more information on the upcoming steps, check the documentation linked above.

3) Send the following XML in the XMPP console.

<iq type='get' to='gmail.com'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>

4) Now get your current status list. Change username to your gmail username before sending

<iq type='get' to='username@gmail.com' id='ss-1' >
  <query xmlns='google:shared-status' version='2'/>
</iq>

This list can be pretty big if you have many saved messages. The output should be something like.

<iq to='username@gmail.com/89089080' from='username@gmail.com' id='ss-1' type='result'>
	<query xmlns='google:shared-status' status-min-ver='2' status-max='512' status-list-max='3' status-list-contents-max='5'>
		<status/>
		<show>dnd</show>
		<invisible value='false'/>
	</query>
</iq>

Observe the invisible value there. That is what we will be manipulating to the our status to invisible.

5) Now, to set your status to invisible, send the following in the xmpp console.

<iq type='set' to='username@gmail.com' id='ss-2'>
  	<query xmlns='google:shared-status' version='2'>
		<invisible value='true'/>
       </query>
</iq>

Although, the pidgin status does not change, you are infact invisible. You can check in gmail or ask someone on your chat list

6) To get out of invisibility, send the following.

<iq type='set' to='username@gmail.com' id='ss-2'>
  <query xmlns='google:shared-status' version='2'>
    <status/>
	<show>dnd</show>
	<invisible value='false'/>
</query>
</iq>

Here the invisible line is important. Other lines are a copy paste of the result of your status list with some minor changes.

This can be a bit tedious, but if anyone is ready to make a plugin out of it, the currently non working one linked above would be a good start.

Enjoy the power of invisibility.

Special thanks to Amod for helping me to test this.

Pidgin Plugins for peace of mind

I guess the title says it all

1) Group Blocker

This plugin allows you to block an entire group in plugin. Nice if you have a group of Irritating people in your chat list.

An Arch package for this is available on AUR here.

2) Away on Lock

Pidgin has a feature to set your status to away after a while if idle. However, this feature is known to be quite buggy especially on the Windows version of Pidgin.

The following plugins can be used for the same –

For Linux – Away on Lock. An arch package for the same can be found on the AUR here.

For Windows – Lock ‘n’ Roll

Lock ‘n’ Roll does not change the status if it is busy, invisible or already away. I see this as a bug in the busy case. The code is quite simple to understand and edit and also has documentation. If anyone has a pidgin windows devel environment, that can be changed easily.

Other Third Party Pidgin Plugins.

Since this is the first post of this year, Happy New Year people

Hashbang #! and amarok1 on Arch

The #! at the start of bash, ruby, python scripts is called the hashbang. Its use with the Amarok install –

One or two days after writing the article about amarok1 installation on Arch, a new version of amarok1 with ruby1.9 support was uploaded. As most of the ruby scripts for amarok1 still work only with ruby1.8, I decided to keep my old version. Today, while I was looking through a few bash scripts, I realized that using #! in the needed ruby scripts was a better option. So, now I use the  AUR package and just change the hashbang lines in my scripts to point to ruby1.8 exec. If only I had realized this earlier

Anyways, more info about hashbang here.

wget : Add progress bar to non verbose mode

Check this bug report for the problem I had with default mode.

wget has four levels of verbosity which are described as below in its man page –

-d --debug
Turn on debug output, meaning various information important to the developers of Wget if it does not work properly. Your system administrator may have chosen to compile Wget without debug support, in which case -d will not work. Please note that compiling with debug support is always safe---Wget compiled with the debug support will not print any debug info unless requested with -d.

-q --quiet
Turn off Wget's output.

-v --verbose
Turn on verbose output, with all the available data. The default output is verbose.

-nv –no-verbose

Turn off verbose without being completely quiet (use -q for that), which means that error messages and basic information still get
printed.

The problem with these is that the verbose mode prints too much info, quiet prints nothing and non-verbose prints info which is not useful in any way.

Installing Amarok 1.4 on Arch Linux

Installing Amarok 1.4 on Arch Linux is a piece of cake. The package is present on AUR and it has patches for Wikipedia problem, the modified cover fetcher and some others. All you need to do is –

yaourt -S amarok1

and you are done. This will get Amarok 1.4 up and running on your system. But making it work is a bit of a problem. As the binaries are installed in a different directory viz. /opt/amarok/ you will need to add that path to your PATH varible. This will make sure amarok starts without the amarokapp error but the collection scanner does not seem to work. And without a collection there is no way I am going to use amarok. I tried to find various ways around this problem (I had Amarok 2 installed the first time this was done, tried installing without it on the system, adding the /opt/ path at the start of $PATH ) but they did not work so I decided to edit the PKGBUILD file provided on the AUR page. Few of the other problems that I have solved here and my assumptions are mentioned below –