Re: anomalous behaviour of ls command

[Greg Wooledge]

On Tue, Jan 30, 2018 at 01:54:36PM -0500, ken young wrote:
> uname output: Linux Microknoppix 4.12.7-64 #13 SMP PREEMPT Tue Aug 15 
> 04:56:38 CEST 2017 x86_64 GNU/Linux
> Machine Type: i686-pc-linux-gnu
> 
> Bash Version: 4.4
> Patch Level: 12
> Release Status: release
> 
>         I have a directory with four files A Z a z only.
>         "ls [A-Z]" displays only 3 files A Z   z       ;a is missing
>         "ls [a-z]" displays only 3 files A   a z       ;Z is missing

The behavior of range expressions in globs depends on your locale
setting.  The legacy range expressions [A-Z] and [a-z] only work
the way you expect when your locale is set to "C" or "POSIX".

If you want to match only uppercase letters (whatever those are in
your locale), you must use [[:upper:]] instead.  To match only
lowercase letters (whatever those are), use [[:lower:]] instead.

See <http://mywiki.wooledge.org/locale> for more details.

wooledg:~$ mkdir /tmp/x && cd "$_"
wooledg:/tmp/x$ touch A Z a z
wooledg:/tmp/x$ ls [A-Z]
A  z  Z
wooledg:/tmp/x$ ls [[:upper:]]
A  Z
wooledg:/tmp/x$ ls [[:lower:]]
a  z
wooledg:/tmp/x$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=