\documentclass{article}
\begin{document}
  \immediate\write18{date > tmpdate.tex}
  \input{tmpdate}
  \immediate\write18{rm tmpdate.tex}
\end{document}

As \write18 is usually disabled on most systems for obvious security reasons, it must be enabled explicitly:

$ latex -shell-escape input_file

More details are available in the MiKTeX documentation under the heading “Running Programs From Within TeX“.

$ ln -s targetfile ../src/targetfile_link

Without a doubt, ‘targetfile_link’ will be a broken symlink since it links to a target that it assumes is in the same directory:

$ cd ../src && ls -l targetfile_link
lrwxrwxrwx 1 mafgani mafgani 5 2010-01-16 18:19 targetfile_link -> targetfile

This is quite unfortunate since it clearly clashes with the way that the linking mechanism should work intuitively.

The solution is to force ln into automatically appending the absolute path to the target files. This can be achieved by using a simple shell script that acts as a wrapper for the real linking command:

#!/bin/sh

# Step through the supplied arguments and append the absolute
# path to targets that exist
for ARG in $@
do
  if [ -e $ARG ]; then
    LNARGS="${LNARGS} ${PWD}/${ARG}";
  else
    LNARGS="${LNARGS} ${ARG}";
  fi
done

# Execute the actual link command with the modified args
exec /bin/ln ${LNARGS};

There are two known caveats:

• The link is ‘sub-optimal’ if created from within the destination directory (the absolute path contains ‘../’s). It will still work however.
• The links will always be absolute. If that is undesirable, save the script as ‘absln’ or something other than ‘ln’.

Using ‘absln’ instead of ‘ln’ in the previously described scenario now produces a working symlink:

$ absln -s targetfile ../src/targetfile_link
$ cd ../src/ && ls -l targetfile_link
lrwxrwxrwx 1 mafgani mafgani 16 2010-01-16 19:13 targetfile_link -> /tmp/files/targetfile

It is a light-weight utility that does one thing only and it does it well: convert between image formats. I’ve been using it for a while now and find that it can greatly reduce files sizes with minimal drop in quality. I’ve even used it to process existing EPS files just to get the reduction in file size. Best of all, it is multi-platform — executables are available for both Windows and Linux on the project homepage.

Goodbye convert and hello sam2p!

The most common approach is to simply redefine the ‘\baselinestretch’ variable in the preamble of the document. The parameter controls the scaling of the space between the bottom of two successive lines of text. Therefore, the definition used to squeeze that space by 2% is:

\renewcommand{\baselinestretch}{0.98}

While that trick alone is sufficient in most cases, it is useful to be aware of other spacing parameters that can be adjusted. The Cambridge University Engineering Department has a nice page with lots of details. I personally find ‘\textfloatsep’ to be one of the more useful ones:

\addtolength{\textfloatsep}{-5mm}

It is used to reduce the amount of space that is usually left between a float and the adjacent text block (e.g. end of caption of a top-figure and the text below).

Just Host offers cPanel as a web frontend for managing and running site related tasks. It’s quite a nice tool but there is one big problem. The interface is literally littered with a bunch of annoying ads and affiliate links. Even more annoying is the fact that there doesn’t seem to be any way of permanently moving these offending boxes to the bottom of the screen. This is where Greasemonkey comes in.

Greasemonkey is a nice little extension for Firefox that allows the execution user scripts to change the way a website looks. userscripts.org is a great place for finding scripts that work on major/popular sites on the internet. A search there didn’t turn up anything useful so I decided to write my own. Install Greasemonkey if you don’t have it already and then click on this link to get the script installed. I’ve also put up a copy on userscripts.org.

The script works by setting the ‘display’ style of the offending div boxes to ‘none’. Firebug is another great tool that makes it a breeze to find out the IDs of the divs that need to be blacklisted.

[Update 10-Nov-2009]: Looks like some sneaky new ads injected using Javascript have shown up on the cPanel sidebar. Unlike the old ad boxes however, these lack div IDs. As a result, it is not possible to simply blacklist them. Fortunately, it also means that it is possible to turn the table around by simply blocking the sidebar divs that have a null ID. The script has been updated.

Before:

Before applying greasemonkey script

After:

After applying greasemonkey script

I really should be working on my thesis and a number of other papers but it does get a bit tiresome. Whenever that happens, I’ll work a bit on the drafts as a distraction and hopefully manage to push a few of them out over the coming weeks…

http://underscorebleach.net/jotsheet/2006/05/move-blogger-to-wordpress

$ psnup -l -2 input.ps output.ps

While psnup is excellent for quick “N-up” conversion jobs, it doesn’t provide much control over the layout. The pstops utility on the other hand allows for fine grained scale, rotation and placement settings for each page that goes into a sheet of the output. The command syntax is a bit more complicated on account of the page specification strings that must now be provided. The following example shows a typical command needed to prepare a document for duplex printing with two pages on each side of a sheet:

$ pstops -pa4 \
  '4:0L@0.8(21cm,-1cm)+1L@0.8(21cm,12.55cm),2R@0.8(0,29.85cm)+3R@0.8(0,16.25cm)' \
  input.ps output.ps

The command is best understood by referring to the relevant section from the manpage:

       Pstops rearranges pages from a  PostScript  document,  creating  a  new
       PostScript  file.   The  input  PostScript file should follow the Adobe
       Document Structuring Conventions.  Pstops can  be  used  to  perform  a
       large  number  of  arbitrary  re-arrangements  of  Documents, including
       arranging for printing 2-up, 4-up, booklets, reversing, selecting front
       or back sides of documents, scaling, etc.

       pagespecs follow the syntax:

              pagespecs   = [modulo:]specs

              specs       = spec[+specs][,specs]

              spec        = [-]pageno[L][R][U][@scale][(xoff,yoff)]

       modulo is the number of pages in each block. The value of modulo should
       be greater than 0; the default value is 1.  specs are the page specifi-
       cations  for  the  pages in each block. The value of the pageno in each
       spec should be between 0 (for the first page in the block) and modulo-1
       (for  the  last page in each block) inclusive.  The optional dimensions
       xoff and yoff shift the page by the specified amount.   xoff  and  yoff
       are  in  PostScript’s points, but may be followed by the units cm or in
       to convert to centimetres or inches, or the flag w or h to specify as a
       multiple  of  the width or height.  The optional parameters L, R, and U
       rotate the page left, right, or upside-down.  The optional scale param-
       eter  scales the page by the fraction specified.  If the optional minus
       sign is specified, the page is relative to the  end  of  the  document,
       instead of the start.

       If  page  specs  are  separated  by + the pages will be merged into one
       page; if they are separated by  they will be  on  separate  pages.   If
       there  is only one page specification, with pageno zero, the pageno may
       be omitted.

       The shift, rotation, and scaling are performed in that order regardless
       of which order they appear on the command line.

I first came across it on this page.

The software equivalent of Etherpad is Gobby. It’s a multi-platform tool that claims to run on Microsoft Windows, Mac OS X, Linux and other Unix-like platforms — making it almost as flexible as a web-based service. There are a number of other advantages:

• Flexibility and security that comes from having absolute control over the sessions.
• Syntax highlighting!