Deane grumbled:
> I've not seen this done, so I don't know if it can be, but... Is there
a way to get $1 from a pair of parens in a regexp into a variable in one
line? That is...
my $foo = 'http://10.20.30.40/gargle';
$foo =~ /(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/;
my $fee = $1;
print "IP = \"$fee\"\n";
> ..is there some way to get the second and third lines into one line?
Well - maybe. But
$foo =~ /(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/;
my $fee = $1;
is a Bad Thing, on its own. Did it match? You don't know. If it didn't,
there's the oft-overlooked issue w/ perl in that "$1" and the rest of the
capture vars retain their old values after a failed match. That is (note
the RE change to 3,3 for the first octet so it fails):
if ( $do_this =~ /(y)/ ) {
my $foo = 'http://10.20.30.40/gargle';
$foo =~ /(\d{3,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/;
my $fee = $1;
print "IP = \"$fee\"\n";
prints:
IP = "y"
You always want to test your matches. What you want to do is have the
match return a list of capture vars:
if ( my ($fee) = $foo =~ /(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/ ) {
print "IP = \"$fee\"\n";
}
else {
print "NO IP found in \"$foo\"\n";
} # if ( my ($fee) = $foo =~
/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/ )
You need the parens around "$fee" to make it into list context, the match
returns the list of capture vars. If you did:
if ( my $fee = $foo =~ /(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/ ) {
that is, scalar context, you get back the true/false (Number of matches,
actually) in $fee. You can get multiple returned values here:
if ( my ($fee, $fie, $foe, $fum ) = $foo =~
/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/ ) {
printf('IP = "%d.%d.%d.%d"%s',
$fee, $fie, $foe, $fum, "\n") ;
using printf is a little more readable esp if the vars can sort line up
under their template markers. The "\n" on the end was one way to avoid \"
you could do
printf("IP = '%d.%d.%d.%d'%s",
$fee, $fie, $foe, $fum) ;
if:
IP = '10.20.30.40'
is acceptable.
Kevin wondered:
> but I thought the general purpose of this listserv was to
> discuss issues related to the ActiveState perl, not coding issue.
Maybe, but its been used as as such for so long, one'd have to go w/ a
"no, its for active perl users to ask perl questions". The unix-user and,
to a lesser extent, the win32-user perl lists have pretty much gone the
same route. I don't imagine there's enough 'just ActiveState' perl issues
to keep a list going ;-> that's a good thing.
a
Andy Bach
Systems Mangler
Internet: [EMAIL PROTECTED]
VOICE: (608) 261-5738 FAX 264-5932
"CM/ECF is a complex unfinished suit. Pull on a loose cuff thread and
your pants fall down." MEC
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