Older blog entries for arauzo (starting at number 20)

28 Jul 2006 (updated 28 Jul 2006 at 13:25 UTC) »
How to print a PDF user manual in an appropriate size

Usually the user manual of the tech gadgets we buy comes on a CD in PDF format. Sometimes there is also a printed copy included. This was my case, but it came in the wrong language. If I wanted the spanish manual, I would have needed to return the camera and wait longer to have it again. So that was not an acceptable option. I have tried to understand portuguese, but unsuccessfull. I have tried without the manual and it was ok for standard features, but... ok, let's print the manual.

The size of the manual is such that four pages fit well on an a4 paper. I have used:

pdf2ps Manual.pdf
psselect -p3-185 Manual.ps sel.ps 
psbook sel.ps | pstops 8:0,1,4,5,2,3,6,7 | psnup -4 -pa4 -b-5cm >out.ps

  1. First line converts it to postscript.

  2. Second line removes some problematic unusefull pages.

  3. Third line:
    • psbook arranges pages to be folded when printed two on each side of paper.

    • pstops arranges pages to have 4 on each side (cutted on the middle and folded each pair.

    • psnup effectively puts 4 pages on each final a4 page with '-b-5cm' used to remove the excesive individual margins of original pages.

More advanced info on making impositions with pstops.

Babel package makes latex indent first paragraph

Latex standard styles, like article or book, do not indent first paragraph, but babel package change this behaviour. For example, it indents all paragraphs when using spanish, even those after a heading.

If you want the first paragraph not being indented, you can comment out these two lines at your language file:

/usr/share/texmf/tex/generic/babel/spanish.ldf
...
%  \let\@afterindentfalse\@afterindenttrue
%  \@afterindenttrue

Of course, you can always manually remove indent starting any paragraph with '\noindent', or disable all paragraph indentation with '\parindent=0cm'.

24 Jul 2006 (updated 19 Jul 2008 at 23:37 UTC) »
Have you ever created thousands of files in /tmp?

We have created up to 2 million files:


arauzo@brain:/tmp $ ls | wc
2099630 2099630 43839565

It was by mistake. You know, that commented line that did not get uncommented, when it should have. I'm starting to think I do very strange things, and they are becomming very strong stress test for Linux.

Anyway, it is not so simple to delete a big bunch of files. The first you probably think of is:


arauzo@neuron2:/tmp$ rm *.net
-bash: /bin/rm: Argument list too long

Yes, I know it is long, but I NEED to remove those files. Let's try another thing:


arauzo@neuron2:/tmp$ for f in *.net; do rm -f $f; done
removed `mlp85_57_24-NI6MxY.net'
removed `mlp85_57_24-NbyBLS.net'
removed `mlp85_57_24-Nc7WVw.net'
...

Nice! This works for thousands of files. But now, what happends with our 2 million files?:


arauzo@brain:/tmp $ rm *.net
Connection to brain closed.
...
arauzo@brain:/tmp $ for f in *.net; do rm -f $f; done
Connection to brain closed.

It crashes! :-( Looks like a 'bug' on bash... :-?

Finally, we have managed to remove the 2 million files in groups by their prefix 32*.net 33*.net 34*.net ...

PD. A more intelligent solution (as it does not need to store the list of files anywhere), suggested by wtanaka and redi:


find /tmp -name "*.net" -print0 | xargs -0 rm -f

Can be 'simplyfied' to:


find -name "*.net" -exec rm -f \{\} \;

PD2. The simplification has an overhead of creating one process per file, while xargs creates a process for a group of files.

How to print short-edge duplex when short-edge duplex does not work in your printer

  1. Everything you print in Linux use to get the form of a postscript document. Just use "print to file" in your application, or pdf2ps and get your file.ps.

  2. Then you can convert your file.ps to another .ps with even pages turned upside-down with this command (using a4 paper, change size to fit your paper):

     pstops "2:0,1U(21cm,29.7cm)" file.ps >fileTurned.ps 

  3. You can see the results with ggv or print it with lp, xpp...
10 May 2006 (updated 10 May 2006 at 17:23 UTC) »

I do not have a blog in spanish, so I write this here though probably it is not interesting to those who do not read spanish.

On this Sunday, 14th of May there is an email convocated demostration on all mayor cities of Spain to ask for decent homes. Against the real estate bubble.

It is time to think, what we are asking for in these demos. I think we should ask for more fiscal help on taxes to those who buy a house to live in.

Demostrations are being been done in Europe against software patents. Among them, we have the photo demostration, where more than 2800 people appear, and the web demostration, where more than 320 sites are registered (and many others unregistered but following the demo).

We need more help. Are US citizens doing something to make people see how bad are software patents? Is anybody trying to change US law?

What do you expect to find, if you search for an "orange diagram"?

Wrong! You find my module to use SNNS neural networks from Orange data mining software. These are the strange things that you discover by looking at the web logs.

By the way, I forgot to post that this fantastic piece of software (OrangeSNNS) was available. ;-)

Late at night, waiting for my script to finish... Well, I did not have a more stupid thing to do, so I found that my weird quotient was 86 .

Long time without writing here... I hope I can avoid this in future. Now just a short note to break the ice.

I have found that blogs can be really useful. My today's personal discovery is a simple and fast implementation of the argmax function in python from Daniel Lemire's blog.

1 May 2004 (updated 1 May 2004 at 19:02 UTC) »

What I called host spam blocking lists are better known as Realtime Blackhole Lists (RBLs). Here there is a deeply studied text against RBL from someone that also had problems with RBLs.

There is also a public statement against RBL's from the Electronic Frontier Foundation (EFF), an organization that I trust. To know that they also agree on this with me makes me happy. ;-)

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