I have a perl module, let's say its called Library.pm, and it contains a lot of subroutines. Some of these subroutines do not return anything, but just print something out. For example I have a subroutine printInformation() that just prints info to STDOUT. eg, 
package Library.pm
printInformation()
{
print(STDOUT,
"Here is some info, damn its not returning a scalar");
}

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The problem with the above subroutine example is that I want to hold on to the string that gets printed to STDOUT (or STDERR), but I cannot modify Library.pm. So instead I need to write LibraryWrapper.pm that massages the subroutines of Library.pm to have returnable scalars, arrays, or hashes, etc. . Below demonstrates what I am trying to do: 
package Library.pm
use Library.pm
printInformationWrapper()
{
my @captureSTDOUT;
my @captureSTDERR;

# Set state so that: 
# @captureSTDOUT is populated with all STDOUT. 
# @captureSTDERR is populated with all STDERR. 

printInformation();

# Set state back to previous
if (@captureSTDOUT > 0) {
 # Deal with it. 
}

return @captureSTDOUT;
}

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Please also bear in mind that I would like a solution that is portable for any platform, and is completely self-contained, ie. all done in one process, (no forks). Lastly, just in case, I know about the backticks operator but it only seems to work on system commands, or more generally commands from the parent environment. It does not work when one perl subroutine calls another in the same process. I'd appreciate the help a lot, thanks.

In reply to In a perl sub, how do I capture STDOUT, STDERR that comes from another perl sub? by seank

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