Converting Latex document to HTML / ODT / DOC

I do all my documents in Latex. Actually i usually use emacs org-mode first and later convert it to Latex, but when it comes to using bibtex, it's all latex. It works great and the output dvi/pdf files look so professional. However recently i had to submit the file in .doc format, and i had a real hard time finding good tools to do that.

There are no direct Latex to .doc converters, so the best bet is to go Latex -> HTML -> DOC. There are lots of Latex to HTML converters like latex2html, tth and hevea, but most of them either don't produce good HTML or mess with bibliography references. But after some research i found the best: TeX4ht

TeX4ht is available in ubuntu/debian repo, so to install

sudo apt-get install tex4ht

Conversion is simple:

htlatex document

(please note, there is no .tex suffix)

This will generate document.html, css and bunch of .png files.

Now to convert it to wordprocessor files (odt, doc..),
1. Open the html file with OpenOffice.org
2. File > Save as
3. Choose the format you want to save it in (odt, doc)

If you have images in the document, they will be linked instead of embedded in the document. To fix this: (source)
1. Edit > Links
2. Click "Break Link" for each image link

mpg123: Lightest mp3 player in Linux

If you are in search of the lightest barebone mp3 player in Linux, nothing can beat mpg123. Unless you want flashy visualizations and playlist management and such, mpg123 can save you a lot of memory and cpu horsepower.

Installation is easy. In Ubuntu,

sudo apt-get install mpg123

Mpg123 comes with loads of options. Check out the man page for details. Here I'm gonna share a few usage tips.

Shuffle-play a directory of mp3s:

mpg123 -CZ /path/to/mp3/folder/*

-Z option is for shuffle, -C is for control. From man page:

-C, --control
  Enable terminal control keys. By default use ’s’ to
  stop, ’p’ to pause, ’f’ to jump forward to the next
  song, ’b’ to jump back to the beginning of the song,
  ’,’ to rewind, ’.’ to fast forward, and ’q’ to quit.
  Type ’h’ for a full  list  of  available  controls.

Equalizer:

Don't fall off your chair! Yes, mpg123 also comes with 32-band equalizer. But there's no inbuilt graphical UI for that, you need to create the plain-text file. There's an editor though if you like, but creating one is not hard either. From man page:

-E file, --equalizer
  Enables equalization, taken from file. The file needs to
  contain 32 lines of data, additional comment lines may be
  prefixed with #. Each data line consists of two floating-
  point entries, separated by whitespace. They specify the
  multipliers for left and right channel of a  certain
  frequency band, respectively. The first line corresponds
  to the lowest, the 32nd to the highest frequency band.
  Note that you can control the equalizer interactively
  with the generic control interface.

I've made one with party feel: party.txt

Usage:

mpg123 -CZ -E party.txt mp3_file

Songs again and again:

Plus if you kind of person who listens to couple of songs again and again for weeks (instead of shuffled huge playlist), then hi5! :) and here's how to do that with mpg123:

mpg123 -CZ song1.mp3 song2.mp3

Making DLink DWL-650+ PCMCIA Wireless card work under linux

The DLink DWL-650+ PCMCIA Wireless card doesn't work on recent Linux distros (I tried Ubuntu Hardy to Jaunty). After plugging in, the system hangs with CapsLock flashing.

Turns out the card is handled by acx module and the support is broken for this card. So use ndiswrapper instead.

First blacklist acx module. Open /etc/modprobe.d/blacklist.conf file and add the following line

blacklist acx

Now install ndiswrapper

sudo apt-get install ndiswrapper-common

Now get the Windows driver for the card from here. Extract the file, go to the winxp folder and,

sudo ndiswrapper -i AIRPLUS.INF

The card should work now.

NTC's GPRS in Linux via Bluetooth using Nokia phone

The following guide explains how to connect to Nepal Telecom's GPRS service from Linux via Bluetooth using Nokia phone. This guide is based on Linux GPRS Guide. The steps have been tested on Nokia 6600, 6630 and 5300 but should work on all Nokia phones.

NTC's GPRS is *really* slow so I won't recommend it for everyday use. However simple mail checking and tweeting ;) should do just fine.

Requirements
1. Nokia Phone
2. Nepal Telecom GPRS Account
3. Bluetooth Dongle (if not inbuilt in your PC/laptop)
4. Linux (the following steps were tested on Ubuntu)

Steps
1. Download ntgprs.tar.gz and extract (ntgprs, ntgprs-wvdial.conf and ntgprs-disconnect)
2. Copy the files to /etc/ppp/peers/ (you need root or sudo access)
3. Turn on Bluetooth on your Nokia phone
4. Plug in Bluetooth Dongle to PC or enable it (if inbuilt)
5. Fire up terminal (the commands to be entered are in bold-face):

Make sure the bluetooth is running on PC:

$ hciconfig
hci0:   Type: USB
BD Address: 11:11:11:11:11:11 ACL MTU: 672:3 SCO MTU: 48:1
UP RUNNING PSCAN ISCAN
RX bytes:149397 acl:1046 sco:0 events:764 errors:0
TX bytes:40320 acl:628 sco:0 commands:74 errors:0

The following command will find bluetooth address of your phone

$ hcitool scan
Scanning ...
00:0E:6D:C2:99:42       Nokia

Create a RFCOMM port and bind it to phone's Bluetooth address.

$ sudo rfcomm bind /dev/rfcomm0 00:0E:6D:C2:99:42 1

Please note that the bluetooth address in the above command should match the address found by 'hcitool scan' command.

Check if the port has been created

$ rfcomm -a
rfcomm0: 00:0E:6D:C2:99:42 channel 1 closed

Now dial.

$ sudo pon ntgprs

--> WvDial: Internet dialer version 1.60
--> Initializing modem.
--> Sending: ATH
ATH
OK
--> Sending: ATE1
ATE1
OK
--> Sending: AT+CGDCONT=1,"IP","internet","",0,0
AT+CGDCONT=1,"IP","internet","",0,0
OK
--> Sending: AT+CBST=0,0,1;+CHSN=6,0,0,0;+CGDCONT=,,"ntnet"
AT+CBST=0,0,1;+CHSN=6,0,0,0;+CGDCONT=,,"ntnet"
OK
--> Modem initialized.
--> Sending: ATD*99#
--> Waiting for carrier.
ATD*99#
CONNECT
~[7f]}#@!}!} } }2}#}$@#}!}$}%\}"}&} }*} } g}%~
--> Carrier detected.  Waiting for prompt.
~[7f]}#@!}!} } }2}#}$@#}!}$}%\}"}&} }*} } g}%~
--> PPP negotiation detected.
Serial connection established.
using channel 9
Using interface ppp0
Connect: ppp0 <--> /dev/rfcomm0
sent [LCP ConfReq id=0x1 ]
rcvd [LCP ConfAck id=0x1 ]
rcvd [LCP ConfReq id=0x0   ]
sent [LCP ConfAck id=0x0   ]
sent [PAP AuthReq id=0x1 user="user" password="pass"]
rcvd [PAP AuthAck id=0x1 ""]
PAP authentication succeeded
sent [IPCP ConfReq id=0x1   ]
rcvd [IPCP ConfReq id=0x0 ]
sent [IPCP ConfNak id=0x0 ]
rcvd [IPCP ConfNak id=0x1   ]
sent [IPCP ConfReq id=0x2   ]
rcvd [IPCP ConfReq id=0x1 ]
sent [IPCP ConfAck id=0x1 ]
rcvd [IPCP ConfAck id=0x2   ]
Cannot determine ethernet address for proxy ARP
local  IP address 10.1.4.101
remote IP address 10.0.0.1
primary   DNS address 202.70.64.5
secondary DNS address 202.70.64.15
Script /etc/ppp/ip-up started (pid 9902)
Script /etc/ppp/ip-up finished (pid 9902), status = 0x0

To disconnect

$ sudo poff ntgprs

Easy bandwidth shaping in Linux

There is an extensive and nicely written HOWTO on this topic but here I'm talking about some really easy to use bandwidth shaping tools -- wondershaper and trickle.

Wondershaper
This is the easiest tool I have found to limit bandwidth of a particular interface. All it takes is,

$ sudo wondershaper {interface} {down} {up}

the {down} and {up} are bandwidth in kilobits. So for example if you want to limit the bandwidth of interface eth1 to 256kbps uplink and 128kbps downlink,

$ sudo wondershaper eth1 256 128

To clear the limit,

$ sudo wondershaper clear eth1

Easy, eh?

Trickle
Unlike wondershaper, which limits the bandwidth to an entire interface, trickle is user-space bandwidth limiting tool. The syntax is,

$ trickle -u {up} -d {down} {program}

Both {up} and {down} and bandwidth in KB/s. Now if you invoke it as,

$ trickle -u 8 -d 8 firefox

It will fire up Firefox, limiting the bandwidth to 8KB/s. This is very useful specially if you are a web developer and want to test your application under various bandwidth conditions.

Furthermore, you can also run trickle as daemon (trickled) which can limit the bandwidth to several programs.