[lug] Perl question: how to print embedded metacharacters

Chip Atkinson chip at pupman.com
Wed Nov 25 09:34:25 MST 2009


Hmmmm... that does work, but isn't it using the bash printf rather than
perl?  My concern is how fast it would be.  I can experiment there though,
and it does work.  

Thanks for your help!

Chip

On Wed, 25 Nov 2009, Jeffrey Haemer wrote:

> Chip,
> 
> Okay.  Would something like this be good enough?
> 
> 
> #!/usr/bin/perl
> 
> while (<>) {
>   $_=` printf "$_" `;
>   print;
> }
> 
> 
> 
> 
> On Wed, Nov 25, 2009 at 9:06 AM, Chip Atkinson <chip at pupman.com> wrote:
> 
> > No, unfortunately.
> >
> > The problem is that the script reads the string in from the command file,
> > so I need to interpret the string before printing it.  Here's another
> > example:
> > ---------------------
> > chip at chip-desktop:~$ cat try2.pl
> > #!/usr/bin/perl
> >
> > #my $kw = 'abc\ndef';
> > #my $nv = "${\($kw)}";
> >
> > while (<>) {
> >  print "$_";
> > }
> > chip at chip-desktop:~$ echo 'abc\ndef' | ./try2.pl
> > abc\ndef
> > chip at chip-desktop:~$
> > ---------------------------------
> > In a sense, I need the opposite of quotemeta -- something that takes in a
> > string and does the metacharacter replacements.
> >
> > I know that something like
> > while (<>) {
> >  s/\\n/\n/g;
> >  # etc. for all metacharacter sequences...
> >  print;
> > }
> >
> > would work but I wanted to avoid the "etc. for all metacharacter
> > sequences"
> >
> > Hopefully that's more understandable.
> >
> > Chip
> >
> > On Wed, 25 Nov 2009, Jeffrey Haemer wrote:
> >
> > > Chip,
> > >
> > > Can you do this instead?
> > >
> > > my $kw = "abc\ndef";
> > >
> > > If not, can you explain in enough detail that I can try again? :-)
> > >
> > > On Wed, Nov 25, 2009 at 8:29 AM, Chip Atkinson <chip at pupman.com> wrote:
> > >
> > > > Greetings,
> > > >
> > > > I'm working on a perl script that reads strings from a configuration
> > file
> > > > and prints them out.  What I'd like to be able to do is have any
> > embedded
> > > > metacharacters interpreted but I'd like to avoid doing the
> > substitutions
> > > > myself.
> > > >
> > > > For example, here is a little script to emulate the problem:
> > > >
> > > > #!/usr/bin/perl
> > > >
> > > > my $kw = 'abc\ndef';
> > > >
> > > > print "$kw";
> > > > ----------------------
> > > > the output is
> > > > abc\ndef
> > > >
> > > > What I want is
> > > > abc
> > > > def
> > > >
> > > > --------------
> > > > I tried to jfgi but no joy.
> > > >
> > > > Thanks in advance.
> > > >
> > > > Chip
> > > >
> > > > _______________________________________________
> > > > Web Page:  http://lug.boulder.co.us
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> > > >
> > >
> > >
> > >
> > > --
> > > Click to Call Me Now! --
> > > http://seejeffrun.blogspot.com/2009/09/call-me-now.html
> > >
> > > Jeffrey Haemer <jeffrey.haemer at gmail.com>
> > > 720-837-8908 [cell],  @goyishekop [twitter]
> > > http://www.youtube.com/user/goyishekop [vlog]
> > >
> >
> > _______________________________________________
> > Web Page:  http://lug.boulder.co.us
> > Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> > Join us on IRC: lug.boulder.co.us port=6667 channel=#hackingsociety
> >
> 
> 
> 
> -- 
> Click to Call Me Now! --
> http://seejeffrun.blogspot.com/2009/09/call-me-now.html
> 
> Jeffrey Haemer <jeffrey.haemer at gmail.com>
> 720-837-8908 [cell],  @goyishekop [twitter]
> http://www.youtube.com/user/goyishekop [vlog]
> 




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