Thoughts regular expressions in, for example sed

[Patrick Asselman]

On 2013-01-12 17:04, Paul Smith wrote:
> I'll repeat something I said the other day: you should be learning a
> more sophisticated scripting language like Perl.  Perl has all the
> capabilities of shell, sed, awk, and just about any other UNIX tool
> built in, plus capabilities none of the others can match.  And it has 
> a
> regular and consistent syntax, ability to handle unusual filenames
> without glitching, etc.  And it is installed, and runs, everywhere.
>
> I've been working on UNIX systems for... a really, really long time
> (since before Linus sat down to write his first kernel).  My personal
> rule is that if a shell script I'm writing ever gets longer than 
> about
> 25 lines or so, OR if it ever seems necessary to use awk, I chuck it 
> and
> write it in Perl instead.  Sed is fine, but if I need awk I might as
> well switch to Perl.

Though Perl is very powerful and you can create very short scripts with 
it (I believe there are even contests for that?), the problem I found 
myself facing was that when I had to modify a script I had written a 
half year ago, I needed to decipher the whole script from scratch. This 
is probably partly due to myself not adding enough comments, partly 
because I don't use it often, and partly also because I'm not a 
programmer. But after switching to Python I was much happier editing 
scripts after long periods of time, because everything is much more 
readable (and yes: probably also much more lengthy).

But of course everything has its own pro's and con's. Python 3 made 
some pretty radical changes to trivial things such as changing the print 
statement into a print() function. Quite annoying to see your scripts 
fail on such trivial statements, but on the other hand: better to change 
it sooner rather than later, if you are going to change it anyway, for 
the benefit of language consistency.

Best regards,
Patrick Asselman