Perl Regular Expression question

WhatsGoingOn

Hi,

This is probably basic enough, but I can't figure it out. I want to do a string replacement in Perl.

I have a file with the following line:

IPAdd = 1xx.xx.xx.xx

and I want to replace it with

IPAdd = 1yy.yy.yy.yy

However, IPAdd 1xx.xx.xx.xx could be any IP Address, so I am searching for IPAdd and I want to replace the entire line with IPAdd = 1yy.yy.yy.yy

What I have so far is:

my $text;
my $string;
my $replace;

$string = "IPAdd";
$replace = "IPAdd = 1yy.yy.yy.yy";
$text =~ s/$string/$replace/g;

However, this writes the line IPAdd = 1yy.yy.yy.yy 1xx.xx.xx.xx
Can anyone please point me in the right direction for this?
To sum it up, I want to search for part of a string and replace that string and all of that strings line with a new string.

Thanks.

forbairt

This may sound bad but have you actually gone through the documentation on regular expressions ?

WhatsGoingOn

forbairt wrote: »

This may sound bad but have you actually gone through the documentation on regular expressions ?

I have, and I know I am missing something obvious, but it is wrecking my head:(

forbairt

ok sorry ... are xx and yy specific numbers that you know ?

WhatsGoingOn

forbairt wrote: »

ok sorry ... are xx and yy specific numbers that you know ?

I will know what yy is, but not what xx is

forbairt

In that case your string I think should be

$string = "IPAdd = 1\d\d\.\d\d\.\d\d\.\d\d";

the \d = number
the \. makes sure its a dot and not a special character

WhatsGoingOn

forbairt wrote: »

In that case your string I think should be

$string = "IPAdd = 1\d\d\.\d\d\.\d\d\.\d\d";

the \d = number
the \. makes sure its a dot and not a special character

The only problem with that is that I am searching for an IP address, and it may not always be in the format above.
e.g. it could be 111.222.33.44 or 111.222.333.44 etc.

It's ok, I'll figure it out, cheers.

forbairt

$string = "IPAdd = 1\d+\.\d+\.\d+\.\d+";

adding a + should do the trick sorry
I normally keep things looking as simple as possiblee where regexp is concerned so when I have to go back over it I know whats happening

\d+ will match 1 or more numbers

WhatsGoingOn

Works perfectly, thanks forbairt