2016-12-28



The question was how to delete a  bunch  of  hidden  directories.
The  user didn't want to use `rm -r .*' because he was unsure how
it would react on `..' -- do you know? For sure?

The brave one would just test it and discover (in the bash):

     $ rm -r .*
     rm: cannot remove directory: `.'
     rm: cannot remove directory: `..'

I suggested to use `.??*', because that usually matches all those
directories you mean, excluding matching `.' and `..'. I use that
from time to time. More exact, but harder to  type  is  `.[!.]*'.
(I'm always a bit unsure with the negation of character class ne-
gation in the shell, and if I'd enter `^'  instead  of  `!',  the
result would be just what I wanted to avoid!)


Interesting is that the mksh does not expand `..*':

     $ ls -d ..*
     ls: cannot access ..*: No such file or directory

The bash, as shown above, does:

     $ ls -d ..*

Likewise, `.*' does not contain `.' and `..' in  mksh.   This  is
described in its manpage:

     Note that mksh (and pdksh) never matches ‘.’ and  ‘..’,
     but AT&T UNIX ksh, Bourne sh, and GNU bash do.

     Note that none of the above pattern elements match  ei-
     ther  a  period  (‘.’) at the start of a file name or a
     slash (‘/’), even if they are explicitly used in a [..]
     sequence;  also,  the  names  ‘.’  and  ‘..’  are never
     matched, even by the pattern ‘.*’.

[0]


[0]  https://debianforum.de/forum/viewtopic.php?f=34&t=163503&p=1115448#p1115448


http://marmaro.de/lue/        markus schnalke <meillo@marmaro.de>