regular expression search/replace question (HELP!!! :)

amytys · 09-06-2004, 01:09 PM

Given the code:

$sDemo = "______";

I want to replace EACH instance of "__" (two underscores) with "_ _" (space in between).

I tried the code:

$sDemo =~ s/__/_ _/g;

Unfortunately, this changes the first instance, but doesn't go on to ask the question if the second "_" in the first pair was also followed by an underscore, and change that, and so on.

So, given seven underscores, "_______", I get "_ __ __ __" instead of what I want, which is "_ _ _ _ _ _ _".

What should my regular expression look like to do what I want?

Also, what if the delimiter that I'm looking for is a pipe? I tried prefixing it with a \, but that didn't seem to work. How does one format the search or replace side to work with pipes as the search/replace char?

Thanks a lot... looks like a GREAT forum!

druuna · 09-06-2004, 01:18 PM

This:

I want to replace EACH instance of "__" (two underscores) with "_ _" (space in between). (dash space dash dash space dash ......)

and this:

of what I want, which is "_ _ _ _ _ _ _" (dash space dash space ........)

is not the same.

If you want the second (which I think you do

):

echo "______" | sed 's/__/_ /g'

Hope this helps.

amytys · 09-06-2004, 01:25 PM

Nope, that doesn't do it.

The proposal,
echo "______" | sed 's/__/_ /g'

would result in "_ _ _ _"

what I would want is "_ _ _ _ _ _ _"

See, the number of underscores in the string doesn't change... I just want to split it up so that I've got a space in between each underscore.

druuna · 09-06-2004, 01:35 PM

That's a typo of mine,sorry:

echo "______" | sed 's/_/_ /g'

There wil be a <space> at the end (not 100% what you want, but cureable....)

Cedrik · 09-06-2004, 01:53 PM

Try this Perl code :

Code:

$sDemo = "______";
$sDemo =~ s/_{2}/_ _ /g;
chop $sDemo;
print "$sDemo\n";

amytys · 09-06-2004, 02:36 PM

Yes, thank you. #5 did what I was looking for!