Wednesday, 12 August 2015

Friday, 5 June 2015

Configuration files for shell scripts

Sometimes it is convenient to pass arguments to a program using configuration files rather than command line arguments. Using a sourced file in shell scripts is a popular approach because it is very easy to implement, however it has two flaws: It is not very easy to validate against malicious input,...

Sunday, 10 May 2015

Of course grepping logs is terrible!

There has been a heated discussion on LinuxFR¹ about a blog article “Grepping logs is terrible” whose author strongly advocates in favour of binary log storage solutions, which perform consistently better than text log storage solutions in any regards. The author, whose name remains undisclosed², presents...

Thursday, 16 April 2015

Organise collections of LaTeX documents with BSD Owl Scripts

Let us discuss how to handle collections of LaTeX documents with the build system BSD Owl Scripts. In our example we pretend that we are preparing an electronic journal and want to distribute each article of the journal as a separate electronic document. Organisation on the file-system We use the following...

Monday, 13 April 2015

Testing complex shell programs without installing them

A simple shell script fitting in one file can easily be tested from the command line. Complex scripts relying on several shell subroutines libraries and other file assets are a bit more complicated to test, because the file assets used by the script lie at different locations on the file system when...

Sunday, 12 April 2015

Delegating complex treatments to filters in shell programs

Novice shell programmers tend to reproduce procedural structures they learnt from classical procedural languages like Pascal or C¹. While it produces results, this approach is catastrophic and complex treatments should be delegated to filters. I will first convince you that catastrophic is not as...

Saturday, 11 April 2015