Very Computer

Hi,
I apologise for potentially stupid question. I'm working through Ellie
Quigley's "LINUX shells by example" and just encountered a problem which I
can't resolve on my own.

When I type
$ grep [A-Z]
and then enter letters from the console, the command seems to be unable to
distinguish between upper and lower cases (I checked in .bash_profile,
there's no alias for "grep -i" there), like this:
aa <--- my input
aa <--- grep's output
AA
AA
BB
BB
11
22
33
which means that the damn thing understands the difference between a letter
and a digit but refuses to distinguish between upper and lower cases.

There is a workaround to use [:upper:] and [:lower:] instead of [A-Z] amd
[a-z] but it's not good enough because all scripts using grep with regular
expressions will fail.

WHAT SHOULD I DO?!!

I'm running Mandrake 7.2, grep's version 2.4.2 (I think).

PLEASE HELP ME SOLVE THIS PUZZLE

Maybe you are inheriting an alias or a shell function from a parent
shell or there is a global alias or shell function.  Have a look in
/etc/profile (and possibly /etc/bashrc).

To help you see what is going on use the ``type'' command as in
these examples:

$ type -a ls
ls is a function
ls ()
{
    /bin/ls -s -F -T 0 --color=yes $*

Quote:}

ls is /bin/ls
$
$ type -a dos
dos is aliased to `dos-sane'
dos is /usr/bin//dos
$

To make sure you use the program without any hidden options refer to
it by its full path-name, e.g. /bin/grep

$ echo -e "abc\nABC" | /bin/grep [A-Z]
ABC
$

Also have a quick look at:

man which
man file

Does it work now?
--
Manfred

Thanks for answering, Manfred, but nothing worked for me. Damn!
I checked all relevant environment variables, runned /bin/grep but it still
returns both "ab" and "AB".

Do you by any chance know which RPM this utility usually comes in? I've got
a copy of earlier Mandrake 7.1 (and, I think, even anchient things like
Caldera 2.1) so could try to use earlier versions of grep -- just to be sure
the problem is in the damn program.

Thanks a lot!

Ok.  It wouldn't be the first time that redface has patched a long
established bugfree utility into a buggy mess.  :(

If you have software development support installed get the source and
compile it yourself.  Gnu grep is available from many sites, I get it
from <http://mirror.aarnet.edu.au/pub/gnu/grep/>

then do this:
    mkdir mynewdir
    cd mynewdir
download the grep source archive.
    tar zvtf grep-2.4.tar.gz | less
this shows you what would be unpacked and where it goes.
    tar zxf grep-2.4.tar.gz
    cd grep-2.4
    ./configure --prefix=/
    make
    make check
All tests should pass.  Now do your own test:
    cd src
    echo -e "abc\nXYZ" | ./grep "[A-Z]"
If that works as it should then become root and:
    make install
Done.

--
Manfred

Looks to me like the problem might be something as simple as your shell
globbing the [A-Z] pattern you're using.  Try instead like:

    grep '[A-Z]' ...

Most shells will glob characters closed into brackets before it even
gets to the called program.

--

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 A computer science reference.

Quote:> Looks to me like the problem might be something as simple as your shell
> globbing the [A-Z] pattern you're using.  Try instead like:

>     grep '[A-Z]' ...

> Most shells will glob characters closed into brackets before it even
> gets to the called program.

Arrrg!

Never occurred to me.
I nearly always use quotes because the regex are normally more complex.

Just checking:
            ~$ mkdir test
            ~$ cd test
            ~/test$ echo [A-Z]
            [A-Z]
            ~/test$ echo [a-z]
            [a-z]
            ~/test$ touch x
            ~/test$ echo [A-Z]
            [A-Z]
            ~/test$ echo [a-z]
            x
            ~/test$ touch A
            ~/test$ echo [A-Z]
            A
            ~/test$ echo [a-z]
            x
            ~/test$

Yes, that explains it.  Thanks!

ALWAYS use quotes with regex!!!

--
Manfred

Thanks a lot for your help, Manfred
It all works perfectly now!