Shell chauvinism ;-D, was Re: popen4 doesn't block?

Terry Hancock hancock at
Wed Jan 29 15:35:47 CET 2003

Jp Calderone wrote:
>   Multi-thousand line programs should probably be written in actual
> programming languages, such as Python.  There's a reason for this,
> discussed below.

There's a lot of reasons. :-D  For one thing, tcsh doesn't even seem to 
have functions -- the best you can do is make each "function" a separate 
file.  Nasty.  I think this is what the bash folks are on about, since bash 
evidently does have functions.

But shell scripts are very concise and clear for simple operations, and it 
is nicer to be able to embed a few commands to do a particular job.  
(Unpack tar file, cd into it, run ./configure, make, make install, and 
sometimes a few other things).

I wound up wrapping the shell execution code into a factory object, so it 
works pretty much like DTMLMethod() or SQL() in Zope now.  A mid-size 
directory holds a group of shell-scripts for installing each package, which 
serves both as program and documentation, since the user can always just 
type the scripts from the shell if they want to do it manually.  I 
abandoned this for the fancy stuff -- instead of using "patch" to fix 
inappropriate upstream makefiles, I just used Python's re module to filter 
them into place.  Works pretty well.

> Python, on the other hand, was designed, in part, to be
> easy to _read_.  This hasn't led to a language that is as easy to type as
> it could be.

In the very simple extreme of scripting a few commands, however, the Python 
is also harder to read, IMHO.  Don't get me wrong, I'm using Python for a 
reason, but I have not found it to be such a strong *scripting* language, 
which I find ironic, since some people seem to think that's what it's for. 
It's like calling the Space Shuttle an airplane, it may be able to glide 
through the air, but that's not what it was made for.


Anansi Spaceworks

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