Why do we need the real world having the net?

How to fix buttons in Ubuntu 10.04

Pablo Rodríguez — Sat, 01 May 2010 19:49:18 +0000

Thanks to the solution number 8 to this issue, I got the code to fix the left-oriented buttons in Ubuntu 10.04.

Here you have the code (it is only one line):

gconftool-2 --type string --set /apps/metacity/general/button_layout "menu:minimize,maximize,close"

Filed under: Ubuntu

Comparing PDF pages automatically

Pablo Rodríguez — Sat, 06 Mar 2010 16:54:27 +0000

I needed to compare whether two PDF documents generated from the same TeX sources where different or not, since the generation method was slightly different for both.

Trying to compare it visually would be crazy, since the document contains more than 1400 pages. So I needed an automatic way to do it.

Albert Astals Cid from the poppler mailing list suggested to use pdftoppm and diff.

The way to automatically compare PDF pages was extremely easy: convert all pages to images, compare each pages and be warned only on the different ones.

After that, it only rests to check visually which differences contain those pages which have images that don’t match.

Filed under: Digital typography, PDF, TeX

Doing arithmetic in TeX

Pablo Rodríguez — Sun, 27 Sep 2009 19:17:34 +0000

I have just discovered accidentally how to perform simple arithmetic operations in TeX:

\number\numexpr 5+5\relax

And this will print the result, not the operands.

Posted in Personal technotes, TeX

\include and \input

Pablo Rodríguez — Sat, 26 Sep 2009 16:44:01 +0000

Thanks to this comment, I have realized the main difference between \include and \input in LaTeX: \include has a page break before and after the file and \input doesn’t.

Posted in Personal technotes, TeX

Magnifying with XeTeX

Pablo Rodríguez — Thu, 13 Aug 2009 06:41:52 +0000

When magnifying with XeTeX using the geometry package is important not to forget that the documentclass should not have the page size set on it, instead of having it set on the proper geometry option.

Posted in Personal technotes, TeX

When openSUSE seems not be able to handle a DHCP connection

Pablo Rodríguez — Mon, 27 Jul 2009 16:20:06 +0000

For some strange reason, my openSUSE 11.1 distribution seems not to be able to negotiate a DHCP Ethernet connection at home. Ubuntu 9.04 and Fedora 11 (live versions) are able to do that using the same computer and connections.

The only way it seemed to work was typing dhcpcd -k eth0 and after that dhcpcd -n eth0 (both as root). I don’t know what does it actually change, since I must keep that window open and the system considers that it isn’t connected.

It might be a bug, but sorry, too tricky to be reported.

Posted in openSUSE, Personal technotes

How to generate a booklet from a PDF file

Pablo Rodríguez — Thu, 06 Nov 2008 23:25:02 +0000

Using ConTeXt (taken from the imposition explanation):

\definepapersize	[filius][width=136mm, height=232mm]
\setuppapersize		[filius][A4,landscape]
\setuparranging		[2UP,doublesided]
\setuplayout [backspace=0pt,
    topspace=0pt,
       width=middle,
      height=middle,
    location=middle,
      header=0pt,
      footer=0pt,
      grid=no, marking=off]
\starttext
\insertpages
  [document.pdf][width=0pt]
\stoptext

You have to replace the document.pdf with the real file name and filius with the original paper size.

Posted in Personal technotes, TeX

Searching for text in directories

Pablo Rodríguez — Tue, 02 Sep 2008 10:55:35 +0000

To find which pure text files contains a given text from the command line, this is the proper command:

grep -ilr "pattern" directory

The -i option makes the search case-insensitive, -r searches the pattern recursively (that is, in the subdirectories that the actual directory might contain), and -l shows the file list where the pattern occurs.

Thanks to Juan Luis Belmonte for the tip (credit where credit is due).

Backing up all user data in Linux

Pablo Rodríguez — Mon, 01 Sep 2008 21:08:23 +0000

One of the most I like most in Linux is the strong separation among user data and system data. This makes installing new versions, or moving data from different hard disks (and other sensitive operations that require all your data).

To copy all user data you need to type:

tar -cvpf compressed-file.tar /home/

This creates (-c) a file (-f) named compressed-file.tar retaining file and folder permissions and storing there all data from the /home/ directory.

To extract this you would only need to type:

tar -xf compressed-file.tar

The -x option specifies the extraction from -f (file).

To restore the data, the operation should be done at the root directory (since files will be extracted with full-path directories).

Connecting two computers using a twisted pair cable (or a switch)

Pablo Rodríguez — Sat, 03 May 2008 20:26:42 +0000

Sometimes being able to connect two computers using a twisted pair cable or a switch is extremely useful for copying data.

Once we have plugged the cable in both computers (or we have plugged both cables in the switch), we must assign a new IP address to both machines:

ifconfig eth0 10.0.0.1 netmask 255.255.255.0

ifconfig eth0 10.0.0.2 netmask 255.255.255.0

To check whether both computers communicate, we must ping each computer from the other one:

ping 10.0.0.1

ping 10.0.0.2

It is important to ping always the other machine, because pinging the same address (i.e., 10.0.0.1 from 10.0.0.1) always works.

If no packet has been lost, computers communicate because both can send a receive packets. But to move files, one must select a proper protocol.

For security reasons, during this connection no computer should be physically connected to the net.

When everything is done, we get the default internet connection configuration again by restarting the system or by running as administrator:

/etc/init.d/network restart