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From: merlyn@iwarp.intel.com (Randal Schwartz)
Newsgroups: comp.lang.perl
Subject: Re: Can I force " expansion on a string?
Message-ID: <1990Aug23.171506.16602@iwarp.intel.com>
Date: 23 Aug 90 17:15:06 GMT
References: <JES.90Aug22174345@mbio.med.upenn.edu>
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Reply-To: merlyn@iwarp.intel.com (Randal Schwartz)
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In-Reply-To: jes@mbio.med.upenn.edu (Joe Smith)

In article <JES.90Aug22174345@mbio.med.upenn.edu>, jes@mbio (Joe Smith) writes:
| 
| Is there function call or idiom to get Perl to do double-quote
| expansion on the contents of a string?  I'm still a little squeamish
| using 'eval...', at least as I understand, it won't do what I want.
| 
| Why, you ask?  Well, I wanted to use perl to do some simple macro
| processing on information read from a file.  If perl would do the
| replacement, it would save scanning the lines explicitly in my code.
| 
| A contrived example which (when run) demonstrates the problem:
| 
| #!/bin/sh
| echo 'The time is now $TIME' | perl -ne '
| 
| 	sub showtime { join("-",@_); }
| 
| 	$TIME = &showtime(localtime(time));
| 
| 	print "
| I want this to print
|   The time is now $TIME,
| not
|   $_";'
| 
| 
| Any suggestions?
| 
| <Joe
| --
|  Joe Smith
|  University of Pennsylvania                    jes@mbio.med.upenn.edu
|  Dept. of Biochemistry and Biophysics          (215) 898-8348
|  Philadelphia, PA 19104-6059

#!/bin/sh
echo 'The time is now $TIME' | perl -ne '

	sub showtime { join("-",@_); }

	$TIME = &showtime(localtime(time));

	s/\$\w+/eval $&/eg; ## insert this

	print '

Simple, short.  Yeah, I used the ugly 'eval' word.  Oh well.

$_='print substr($_,25,25); "Just another Perl hacker,";'; eval
-- 
/=Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ==========\
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