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print if defined statement to file

regex2012
User

Apr 19, 2016, 9:23 AM

Post #1 of 3 (1678 views)

print if defined statement to file	Can't Post

I am trying to print this to a file:

Code

open my $FH2, '<', '/tmp/testq.txt' or die "unable to open file 'file' for reading : $!"; 
open my $FH6, '>', '/tmp/tst.txt' or die "unable to open file 'file' for reading : $!"; 
my %duplicates; 
while (<$FH2>) { 
    print if defined "$duplicates{$_},"; 
    $duplicates{$_}++; 
}

but I haven't been able to . I am not sure where to indicate the file handle in this statement to get it to print the duplicate line to /tmp/tst.txt.

Can anyone help?

(This post was edited by regex2012 on Apr 19, 2016, 9:24 AM)

BillKSmith
Veteran

Apr 19, 2016, 10:40 AM

Post #2 of 3 (1673 views)

Re: [regex2012] print if defined statement to file [In reply to]	Can't Post

Code

print {$FH6} $_ if defined $duplicates{$_};

Note: The braces are not required, but they make the statement easier to read because emphasize the difference between the filehandle and the data.
Good Luck,
Bill

FishMonger
Veteran / Moderator

Apr 19, 2016, 12:01 PM

Post #3 of 3 (1668 views)

Re: [BillKSmith] print if defined statement to file [In reply to]	Can't Post

It should be noted that the braces would be required if the filehandle was not a plain scalar.

# braces not requried

Code

print {$FH6} $_ if defined $duplicates{$_};

# braces are required

Code

print { $FH[6] } $_ if defined $duplicates{$_};

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