Mike Meyer <[EMAIL PROTECTED]> writes:
> "Mark de+la+Fuente" <[EMAIL PROTECTED]> writes:
>
> > I need to write simple scripts for executing command line functions.
> > Up till now I've used C-Shell scripts for this, but I'm looking for
> > a better alternative. And I keep reading about how “easy” it is to
> > program with python.
>
> As others pointed out, Python isn't a shell, or even a shell scripting
> language, so it doesn't handle what you're doing in a "natural"
> way. Because of that, it may not be the language for you. Python has
> features that work well for building large systems, but those tend to
> cause extra work when you want to do things that other languages make
> simple.
I agree with this approach. For me, there has to be a certain level of
complexity before I reach for python as a tool. This usually involves
one or more of the following:
1: text processing involving multiple files. For example, running
statistics on file A, looking up values stored in file B.
2: cases where the overhead of repeatedly opening processes and pipes
becomes unacceptable.
For example:
for f in file/*; do
cp $f $f.bak
sed -e 'something' < $f.bak > $f
done
This works well with small numbers of files. But even though sed is
quicker than python, starting a new sed process with every iteration
quickly stacks up. Rewriting the entire thing to run as a single
process can dramatically improve performance. Although this might be a
case of premature optimization.
3: cases where figuring out how to do something using one of the POSIX
shell utilities makes my head hurt.
Personally, I hate popen and avoid using it when possible. There is
nothing wrong with sh as a glue language when all you need is something
like: grep text file | filter | filter > output_file.
> <mike
> --
> Mike Meyer <[EMAIL PROTECTED]>
> http://www.mired.org/home/mwm/
> Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.
--
Kirk Job-Sluder
"The square-jawed homunculi of Tommy Hilfinger ads make every day an
existential holocaust." --Scary Go Round
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