perl substitution question

[Jeff Picton]

Hi all

I have a file as follows :-

juve00_04070706

and require to substitute using perl syntax =~s/ etc everything after the _ to become :-

juve00_********

Can anyone help ?

[Tom Maloy]

You can try this:

echo test_change | perl -p -e 's/_.*/done/'

which will change test_change to testdone.

If you are just trying to change a file name while running ksh, you do not need to use perl, you can use this:

fn=test_change
newfn=${fn%_*}done
echo $newfn

The "%" tells ksh to remove the small right pattern that matches "_*", where "*" is a wild card that matches all characters.

[Jeff Picton]

Hi

This is embedded within a perl script, so I am looking for something like :-

filename=juve00_04050607

$filename2=~s/_*/********/ (but this does not work)

I need to substitute everything after the underscore to be *

Thanks

[RAC_1]

Not per, just awk.

echo "juve00_04050607"|awk -F "_" '{print $1,"_********"}'

Anil

[Jeff Picton]

Hi

It must be perl - some sort of substitution or translation, i think

[Hein van den Heuvel · Accepted solution]

To indicate a series of anything you use .* in perl, not just the *
So in it's simplest form your problem can be solved by:

$filename=shift; # take from command line
$filename=~ s/_.*$/_******/;
print "$filename\n";


But what is your exact problem definition?
The last underscore?
Replace the tail wih a fixed series of stars, or wiht as many stars as there where characters? numbers only?
Here is a more elaborate solution replacing the chracters following the last understcore with as many stars:

$filename=shift;
if ($filename =~ /(.*_)(.*)$/) {
$head = $1;
$tail = $2;
$tail =~ s/./*/g;
$filename = $head . $tail;
}
print "$filename\n";


You may want to read up more on regular expression, the 'tr' function, the 's' functions and perhpas also check out 'rindex' and 'substr'.

Enjoy,
Hein.

[Jeff Picton]

Thanks Hein you got what I anted