assign s/// value to a scalar
#!/usr/bin/env perl
use strict;
use warnings;
my @array = qw (
http://abc.com/files/randomthings/A/1.html
http://abc.com/files/randomthings/A/2.html
);
for ( @array ) {
# This works
# s!/A/\d+.html$!!; $url = $_;
# Doesn't work ~ gives 1
( my $url ) = ( $_ ) =~ s!/A/\d+.html$!!;
print $url . \n;
}
__END__
I want to remove the '/A/1.html' and assign the remaining value i.e. link to
$url
But all I get is 1 as value of $url which I think is return value that
substitution worked.
How can I remove '/A/1.html' and assign remaining $_ to $url?
Re: assign s/// value to a scalar
raphael() wrote:
#!/usr/bin/env perl
use strict;
use warnings;
my @array = qw (
http://abc.com/files/randomthings/A/1.html
http://abc.com/files/randomthings/A/2.html
);
for ( @array ) {
# This works
# s!/A/\d+.html$!!; $url = $_;
Not quite, that should be:
s!/A/\d+\.html$!!; $url = $_;
Unless the . character is escaped it will match *any* character.
# Doesn't work ~ gives 1
( my $url ) = ( $_ ) =~ s!/A/\d+.html$!!;
print $url . \n;
}
__END__
I want to remove the '/A/1.html'
That means that you want to modify @array? Do you really need to?
and assign the remaining value i.e. link to
$url
But all I get is 1 as value of $url which I think is return value that
substitution worked.
How can I remove '/A/1.html' and assign remaining $_ to $url?
If you just want to assign everything before '/A/1.html' to $url then:
( my $url ) = m!(.*)/A/\d+\.html$!;
If you really need to modify @array then go with your commented out code
at the top of the loop.
John
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Re: assign s/// value to a scalar
On 2010.03.12 00:33, John W. Krahn wrote:
raphael() wrote:
#!/usr/bin/env perl
use strict;
use warnings;
my @array = qw (
http://abc.com/files/randomthings/A/1.html
http://abc.com/files/randomthings/A/2.html
);
for ( @array ) {
# This works
# s!/A/\d+.html$!!; $url = $_;
Not quite, that should be:
s!/A/\d+\.html$!!; $url = $_;
Unless the . character is escaped it will match *any* character.
# Doesn't work ~ gives 1
( my $url ) = ( $_ ) =~ s!/A/\d+.html$!!;
print $url . \n;
}
__END__
I want to remove the '/A/1.html'
That means that you want to modify @array? Do you really need to?
and assign the remaining value i.e. link to
$url
But all I get is 1 as value of $url which I think is return value
that
substitution worked.
How can I remove '/A/1.html' and assign remaining $_ to $url?
If you just want to assign everything before '/A/1.html' to $url then:
( my $url ) = m!(.*)/A/\d+\.html$!;
If you really need to modify @array then go with your commented out code
at the top of the loop.
I applaud the OP for his question ;)
After I changed some of the sample by removing the use of $_, there were
certain circumstances where having the parens were necessary, and other
times not.
Am I correct in thinking that this:
$url = $file =~ m{ (.*) /A/\d+.html }x;
...assigns '1' to $url because =~ binds tighter and assigns a 'true'
value to $url, whereas:
( $url ) = $file =~ m{ (.*) /A/\d+.html }x;
...$url here is evaluated first, and assigned the actual string
afterwards? iow, is it simply an arithmetic thing, that can also be seen
as this:?
( $url ) = ( $file =~ m! (.*) /A/\d+.html !x );
D'oh! I just answered my own question. Learn something new everyday,
even though it's a principle that I've known for years, but just didn't
apply it...
( my $this ) = ( ( $url ) = ( $file =~ m! (.*) /A/\d+.html !x ) );
print $url :: $this\n;
Steve
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Re: assign s/// value to a scalar
SB == Steve Bertrand st...@ibctech.ca writes:
SB Am I correct in thinking that this:
SB $url = $file =~ m{ (.*) /A/\d+.html }x;
SB ...assigns '1' to $url because =~ binds tighter and assigns a 'true'
SB value to $url, whereas:
SB ( $url ) = $file =~ m{ (.*) /A/\d+.html }x;
SB ...$url here is evaluated first, and assigned the actual string
SB afterwards? iow, is it simply an arithmetic thing, that can also be seen
SB as this:?
nope. it is scalar vs list context, not precedence.
the () makes the assignment to $url happen in list context. the m// op
in list context will return the list of grabs (with some variations
based on the /g modifier). in scalar context m// only returns a boolean
if the match succeeded or not.
SB ( $url ) = ( $file =~ m! (.*) /A/\d+.html !x );
SB D'oh! I just answered my own question. Learn something new everyday,
SB even though it's a principle that I've known for years, but just didn't
SB apply it...
that didn't change anything. =~ binds tighter than = anyway. it is still
context that does it.
SB( my $this ) = ( ( $url ) = ( $file =~ m! (.*) /A/\d+.html !x ) );
SB print $url :: $this\n;
that shouldn't make any difference to assigning $url in list context.
uri
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