Altered behaviour of grep

Altered behaviour of grep

[Fergus Daly]

grep -Pl "\xmn"
used to find files containing the ASCII character mn. For instance
grep -PL "\x0d" or "\x0a" or usefully "\x00".
This seems to have been lost with the current version.
Is this an error? If not, can anybody tell me what new syntax will recover the old behaviour?
Thank you.
Fergus 

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RE: Altered behaviour of grep

[Fergus Daly]

grep -Pl "\xmn"
used to find files containing the ASCII character mn. For instance
grep -PL "\x0d" or "\x0a" or usefully "\x00".
       ^
I did mean grep -Pl in both cases.
Fergus
 

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Re: Altered behaviour of grep

[Corinna Vinschen]

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On Mar 24 08:07, Fergus Daly wrote:
> grep -Pl "\xmn"
> used to find files containing the ASCII character mn. For instance
> grep -PL "\x0d" or "\x0a" or usefully "\x00".
> This seems to have been lost with the current version.
> Is this an error? If not, can anybody tell me what new syntax will recover the old behaviour?

I just tested this on Cygwin and Fedora 21, both with grep 2.21:

  $ cat x.sh
  #!/bin/sh
  echo ${0##*/}
  $ grep -Pl '\x30' x.sh
  x.sh
  $ grep -Pl '\x0a' x.sh
  $ 

Same result on both systems, so it finds characters in lines, but not
the line separator itself.  If that worked before, this looks like an
upstream change to me.

A bit of digging shows this thread on the bug-grep mailing list:
http://lists.gnu.org/archive/html/bug-grep/2015-03/msg00015.html

And indeed, if I add a NUL byte to the file and search for it:

 $ grep -Pl '\x0' x.sh
 $ grep -aPl '\x0' x.sh
 x.sh

This does not work for the CR or LF, though.  You may want to discuss
this on the bug-grep ML.


Corinna

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Corinna Vinschen                  Please, send mails regarding Cygwin to
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