I get the following message: Use of uninitialized value in concatenation (.)

You're using a version of Perl older than 5.8.0, when open(STDOUT, '>', \$buf) was introduced. Before 5.8, \$buf would be stringified to something like SCALAR(0x1ab2760). The output ends up in a file by that name instead of going to $buf, so $buf is still undefined when you go to inspect it.

Before 5.8, you had to use IO::String or IO::Scalar.

Also, what is the structure under my ($buf); in your code?

It creates a new scope. This causes local *STDOUT; to be undone (thus restoring the original STDOUT) before the last print.

what is the significant of "qw"

qw[ some args here ]
is the same thing as
('some', 'args', 'here')
See perlop.

In reply to Re^3: Need Help: Capture Print Outputs from a Function by ikegami
in thread Need Help: Capture Print Outputs from a Function by mnj200g

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