Problems with find, xargs and egrep

Question

I this is what I what I'm trying to end up with (except working)

find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 egrep -vZ 'vvv|iii'

What am I doing wrong?

$ ll
total 0
-rw-rw-r-- 1 yyy yyy 0 Sep 18 10:36 iii.txt
-rw-rw-r-- 1 yyy yyy 0 Aug 29 10:35 old1.txt
-rw-rw-r-- 1 yyy yyy 0 Aug 29 10:35 old2.txt
-rw-rw-r-- 1 yyy yyy 0 Aug 29 10:35 old3.txt
-rw-rw-r-- 1 yyy yyy 0 Nov 16 09:36 vvv.txt
-rw-rw-r-- 1 yyy yyy 0 Nov  5 09:41 young.txt 
$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 egrep -viZ 'vvv|iii'
$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 egrep -vilZ 'vvv|iii'
$    find ./ -mindepth 1 -type f -mtime +60 -print0 
./old3.txt./old1.txt./old2.txt$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 egrep 'old'
$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 grep 'old'
$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 grep 'o'
$    find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 grep '.*o.*' 
$    find ./ -mindepth 1 -type f -mtime +60 | xargs egrep 'o'
$    find ./ -mindepth 1 -type f -mtime +60 | xargs egrep '.*o.*'
$    find ./ -mindepth 1 -type f -mtime +60
./old3.txt
./old1.txt
./old2.txt
$    find ./ -mindepth 1 -type f -mtime +60 | grep 'o'
./old3.txt
./old1.txt
./old2.txt
$    find ./ -mindepth 1 -type f -mtime +60 | xargs grep 'o'
$    find ./ -mindepth 1 -type f -mtime +60 -print | xargs grep 'o'
$    find . -name "*.txt" | xargs grep "old"
$    find . -name "*.txt"
./old3.txt
./vvv.txt
./iii.txt
./old1.txt
./old2.txt
./young.txt
$ find ./ | grep 'o'
./old3.txt
./old1.txt
./old2.txt
./young.txt
$ find ./ | xargs grep 'o'
$

I need the grep because the exclude list will come from a file in the end so just using find to filter isn't quite enough. I'd like the grep to return a NUL terminated list, too. And I am going to pipe the result of this to something else after so I don't know if the find option -exec would be appropriate.

Things I've looked at:

• https://stackoverflow.com/questions/1362615/how-to-find-files-containing-a-string-using-egrep
• http://www.unixmantra.com/2013/12/xargs-all-in-one-tutorial-guide.html

$ bash -version
GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu)
Copyright (C) 2005 Free Software Foundation, Inc.
$ cat /proc/version
Linux version 2.6.18-371.8.1.0.1.el5 (mockbuild@ca-build56.us.oracle.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)) #1 SMP Thu Apr 24 13:43:12 PDT 2014

disclaimer: I do not have a lot of linux or shell experience.

Answer 1

It looks like you want to grep on filenames, buf if you do:

find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 egrep -vZ 'vvv|iii'

the xargs actually presents the list of files coming out of find as argument to egrep.

What you should do to handle the NUL terminated input (from -print0)

find ./ -mindepth 1 -type f -mtime +60 -print0 | xargs -0 grep -EvzZ 'vvv|iii'

(egrep is deprecated, that is why I changed it to grep -E)

From man grep:

   -z, --null-data
          Treat the input as a set of lines, each  terminated  by  a  zero
          byte  (the  ASCII NUL character) instead of a newline.  Like the
          -Z or --null option, this option can be used with commands  like
          sort -z to process arbitrary file names.

   -Z, --null
          Output  a  zero  byte  (the  ASCII NUL character) instead of the
          character that normally follows a file name. 

So you need both -z and -Z