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Re: tieing STDIN & STDOUT using IO::Scalar for use inside an eval

by ikegami (Pope)
on Sep 11, 2004 at 21:41 UTC ( #390320=note: print w/replies, xml ) Need Help??


in reply to tieing STDIN & STDOUT using IO::Scalar for use inside an eval

I don't have IO::Scalar installed, so I can't help you with that module. However, you can do it without IO::Scalar in 5.8.0:

# This \$var syntax of open() requires Perl 5.8.0 or higher. use 5.8.0; my $input = "test\nfoo\nbar\n"; my $output = ''; my $code = 'print while (<STDIN>)'; { local *STDIN; open(STDIN, '<', \$input) or die("Can't open string for reading.\n"); local *STDOUT; open(STDOUT, '>', \$output) or die("Can't open string for writing.\n"); eval "$code"; } print("\$output contains:\n$output"); __END__ output ====== $output contains: test foo bar

A more general example:

# This \$var syntax of open() requires Perl 5.8.0 or higher. use 5.8.0; my $input = "test\nfoo\nbar\n"; open(my $old_stdin, "<&STDIN") or die("Can't dup STDIN: $!.\n"); close(STDIN); open(STDIN, '<', \$input) or die("Can't open string for reading\n"); my $output = ""; open(my $old_stdout, ">&STDOUT") or die("Can't dup STDOUT: $!.\n"); close(STDOUT); open(STDOUT, '>', \$output) or die("Can't open string for writing\n"); print($_) while (<STDIN>); print $old_stdout ("\$output contains:\n$output"); __END__ output ====== $output contains: test foo bar

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