Thursday, September 17, 2009

Green IT - a GSoC topic?

I'm back from the conference at Berlin "Faktor X - Tag der natürlichen Ressourcen", a side-conference of the World Resources Forum 2009 in Davos.

It was pretty interesting, although the topic is not new. If you don't know it: We are running out of (several) resources. The main topics going through the media are often energy and oil. Well, several metals will become much more problematic much more earlier! So, what is the aim: material-, product- and production-efficiency and recycling/upcycling(/downcycling).

One of the topics mentioned at the conference was the IT industry. One of the keywords is green IT - more efficiency through IT, more efficiency by more efficient hardware, better recycling of hardware, .... Another point was more efficiency by more efficient software. One of the questions mentioned was “how much resources costs a click at google?”. I think, one can adapt this question to almost every software. We have several software, which is widely used. I'll just mention the apache web-server. Would't it be good to know, that this widely used software won't waste CPU cycles for nothing?

So what about a GSoC project checking such often/widely used software for efficiency (besides checking for buffer or heap overflows or NULL pointer dereferences)? Can anybody imagine such a project? What is your opinion?

Tuesday, September 15, 2009

Writing manual pages in GROFF (1)

I always wanted to write a short howto for Debian package maintainers, how to write a manual page in GROFF. This is useful for short documents (for longer documents, docbook/docbook-xsl can be a good choice). I already have written some parts. However, here is the first part of hints. More might follow later.

The delimiter in the NAME section

The name section is (probably) the only place, where exactly one hypen-minus \- must appear. The hyphen-minus is the delimiter between the command name and one-line description.

foo-bar \- foos the template foo-what-bar

Typical mistakes regarding paragraphs

Using a .PP macro directly following a .SH or .SS macro is useless. This macro should be used between paragraphs:

The program follows the usual GNU command line syntax, with long options starting with
two dashes (`\-').
A summary of options is included below.

Options/File descriptions

To describe options or files it's usually useful to make use of the .TP macro.

.B \-f, \-\-force
Force the execution of the specified command.
.I ~/.foobar
Per user configuration file.

To create more than one intended paragraph the .IP macro can be used.

.B \-f, \-\-force
Force the execution of the specified command.
This option has no effect in conjunction with \fB\-\-foo\fP.

Avoid hyphenation in URLs/URIs/paths

Usually we don't want URLs or URIs to be hyphenated. This can be done using the \% sequence. Typical examples:

A short tutorial is available online at \fI\%http://foo.tld/some/path/here/manual.html\fP.
On a Debian system the complete text of the GNU General Public License
version 2 can be found in the file \fI\%/usr/share/common-licenses/GPL\-2\fP.

Referencing persons and their mail address

The common markup is to write the person name in bold letters and the mail address in roman letters is put into angle brackets. It's usually a good idea to mark where the mail address starts and ends. We can use the \& sequence as shown in the following example:

\fBDaniel Leidert\fP <\&\&>