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From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: "Out of memory!"?
Message-ID: <8754@jpl-devvax.JPL.NASA.GOV>
Date: 16 Jul 90 21:58:49 GMT
References: <482@sunny.ucdavis.edu> <484@sunny.ucdavis.edu>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 27

In article <484@sunny.ucdavis.edu> poage@sunny.ucdavis.edu (Tom Poage) writes:
: So why is <STDERR> expanded to a list in the inner grep of
: 
: 	if (@errs = grep(s/^/\t/, grep(!/^SQL:/, <STDERR>))) {...
: 
: where
: 	if (@errs = grep( do{/^SQL:/ ? undef : s/^/\t/o;}, <STDERR>)) {...
: 
: is not?

The manual currently says, under grep:

             Note that, since $_ is a reference into the array
             value, it can be used to modify the elements of the
             array.  While this is useful and supported, it can
             cause bizarre results if the LIST contains literal
             values.

That last bit should probably say

             ...cause bizarre results if the LIST is not a named array.

What you are doing, I believe, is modifying temporary stack values that
are being freed when the grep exits.  Don't do that.  It's erroneous,
in language-lawyerese.

Larry