Re: problems with grep

On 2006-11-15, ltarc3@xxxxxxxxx wrote:
I'm having a weird problem with grep. The context isn't that
important, but I will give it to you anyway.

I want to write a script that will look at other scripts and find
variables that are all caps, underscores, and digits. I had a fairly
complicated command with seds and awks and greps that was giving me
problems. I worked my way back to the simplest of greps where I am
just trying to match one uppercase character and now I am absolutely
stymied.

I've run this on FC3, CentOS 4.3.

Am I missing something obvious?? Here is an example:

[root@myhost tmp]# cat testfile
ABC=
abc=
XYZ=
xyz=
123
ABC_123
abc_123
XYZ_123
xyz_123

[root@myhost tmp]# grep "[ABCDEFGHIJKLMNOPQRSTUVWXYZ]" testfile
ABC=
XYZ=
ABC_123
XYZ_123

[root@myhost tmp]# grep "[A-Z]" testfile
ABC=
abc=
XYZ=
xyz=
ABC_123
abc_123
XYZ_123
xyz_123

Why is this matching lower-case strings?

Presumably because your locale folds interleaves and lower case to
emulate case insensitivity.

[root@myhost tmp]# grep "^[A-Z_0-9]" testfile
ABC=
XYZ=
xyz=
123
ABC_123
XYZ_123
xyz_123

And why does this match xyz but not abc ????

Your collation sequence is probably aAbBcCdDeE....xXyYzZ, so [A-Z]
does not include "a".

It's just so weird.

I always use LC_ALL=C.

--
Chris F.A. Johnson, author <http://cfaj.freeshell.org/shell>
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
===== My code in this post, if any, assumes the POSIX locale
===== and is released under the GNU General Public Licence
.

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