open FH, '<', 'myfile'; print FH, "something\n"; #### No comma allowed after filehandle at ... #### open my $fh, '<', 'myfile'; print $fh, "something\n"; #### open local *FH, '<', 'myfile'; while () { # do something } close FH; #### #!/usr/bin/perl use Test2::V0; package Foobar; our $foobar = "foobar\n"; our @foobar; sub use_fh { # unlocalized use of FH in separate package open FH, '<', \$foobar; @foobar = ; close FH; } package main; my $foo = "foo\n"; my $bar = "bar\n"; my $baz = "baz\n"; my @baz; sub use_localized_fh { # protect caller's FH open local *FH, '<', \$baz; @baz = ; close FH; } sub close_fh { # unlocalized use of FH close FH; } # open now, use later open FH, '<', \$bar; my @foo; # create new scope { # use localized FH, protecting handle opened on \$bar open local *FH, '<', \$foo; # call sub that uses localized FH use_localized_fh; # call sub in other package that uses FH Foobar::use_fh; # FH still intact @foo = ; close FH; } is \@baz, [$baz], 'got $baz in sub'; is \@Foobar::foobar, [$Foobar::foobar], 'got $Foobar::foobar in foreign sub'; is \@foo, [$foo], 'good: got $foo'; { open local *FH, '<', \$foo; # call sub that closes FH close_fh; @foo = ; close FH; } is \@foo, [], 'bad: FH was closed in sub'; # FH at this scope is still untouched my @bar = ; close FH; is \@bar, [$bar], 'good: got $bar'; done_testing;