for each in ‘ls *.cfg‘;

Are the following:

1) you are starting another process to handle this
2) you are neglecting files with spaces in the name(which makes it wrong).

That’s what makes the proposed loop wrong. The sed -i solution is the best, but the -i isn’t posix.

Both the original article and Tal’s answer use “for each in…”, but the original article uses “ls *.cfg” whereas Tal only uses “*.cfg”

The “ls” part is the difference…

And note that if I remember correctly, “for … in” will only work for the *sh family and not *csh shells, so I’d say there is no ‘correct’ way ;)

For example:

ecrist@leopard:~-> each in *.txt ; do cat $each
each: Command not found.
each: Undefined variable.

Thus the example becomes
sed -i .bak ’30,35s/^/#/’ *.cfg

Why not just: for each in *.cfg; which also has the added benefit of being correct.

Another great scripting language is Expect (which is a TCL extension).

Between the two I’ve done some neat automated scripts.

So the first example can be something like:

sed -i .bak '30,35s/^/#/g' *.cfg


Nifty, huh?