It's not that much effort :) You could start with
just the READLINE method, and add more functionality later, if the
need should arise...
Here's a simple example implementing READLINE and PRINT functionality:
#!/usr/bin/perl
package MyFH;
sub TIEHANDLE {
my $class = shift;
return bless { @_ }, $class;
}
sub READLINE {
my $self = shift;
print "reading line from remote file $self->{file} ...\n";
# ... (your implementation here)
my $line = "foo\n";
my @lines = ("foo1\n", "foo2\n");
return wantarray ? @lines : $line;
}
sub PRINT {
my $self = shift;
print "writing line(s) to remote file $self->{file} ...\n";
# ... (your implementation here)
print "wrote: @_\n";
}
package main;
use Symbol 'gensym';
my $fh = gensym(); # get ref to anonymous glob
tie *$fh, "MyFH", "file" => "foo.txt";
my $line = <$fh>;
print "read: $line\n";
print $fh "bar", "baz";
Outputs:
reading line from remote file foo.txt ...
read: foo
writing line(s) to remote file foo.txt ...
wrote: bar baz
(Similarly, you could make use of
Tie::Handle / Tie::StdHandle)
Update: the benefit of using a tied filehandle would also be that
you could more easily make your remote SSH connection handle act like a
full-fledged drop-in replacement for a regular filehandle, so existing
code making use of <$fh> and print $fh ..., etc. wouldn't
have to be modified. This might not seem important now, but who knows
when you'll need it...
While you can overload the diamond operator, attempting to
override/redefine print would soon turn into a major show stopper.
Problem is that the print built-in doesn't have a prototype,
at least not one that you could express with Perl's current prototyping
mechanism (for this reason prototype 'CORE::print' is returning
undef, btw). Its implicit prototype has been coded right into
Perl's parser. This means that you cannot write a regular Perl subroutine
which would be treated syntactically like the built-in print.
In particular you can't get the "comma being absent" after the $fh in print $fh @args to
work as desired (you'd get a syntax error if you tried). With a
tied filehandle you don't have such problems.
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