Re^5: Why do we need a \n with do FILENAME?

which might have led ikegami into thinking that the file should always return true

You could require your included file to return something defined. Requiring the included file to return something true is much clearer and simpler, though, and Perl programmers are already accustomed to doing that.

Comment on Re^5: Why do we need a \n with do FILENAME?

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Re^6: Why do we need a \n with do FILENAME? by rovf (Priest) on Jul 08, 2010 at 07:58 UTC
I would agree with you if the only purpose of `do` would be to "load subroutines and initialization code at runtime" in a similar way as `require` does, but for those (rare?) cases this should be done repeatedly. However, from my understanding of do, this function is much more general: It is, in spirit, much more like `eval`, only that the evaluated code resides in a file, not in a string or block. This can, IMO, not only seen from the description of `do`, but also from the fact that `$@` is set after an exception. We wouldn't place the requirment, that code evaluated by `eval` should return a true value unless it fails, do we? I, personally, would say that the same applies to `do`. Maybe our different views in that matters come from the fact that I'm using `do` in a different way. We are using it to inject (for purpose of debugging) arbitrary code at specific "hook point" in a running application. -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l] [select]
Re^7: Why do we need a \n with do FILENAME? by ikegami (Patriarch) on Jul 08, 2010 at 17:06 UTC
It is, in spirit, much more like eval, only that the evaluated code resides in a file, not in a string or block The reason for requiring for avoiding undef has nothing to do with the purpose of function, so this doesn't matter. We wouldn't place the requirment, that code evaluated by eval should return a true value unless it fails, do we? What does matter is the interface provided by the functions. `eval` has a different interface, so it really doesn't matter what you do with `eval`. However, it is indeed quite common to have `eval`'s body return true. `my $foo = eval ... or die("...: $@");` [download]	[reply] [d/l] [select]