Re: suggestion to avoid erroneous lines in findmnt/lslocks/...

[Karel Zak <kzak@redhat.com>]

On Mon, Aug 06, 2012 at 03:44:21PM +0100, Pádraig Brady wrote:
> I did a quick test...

 Thanks, I'll use it in regression tests ;-) (I was busy yesterday to
 write any reg.tests.)

> TARGET                 SOURCE     FSTYPE OPTIONS
> /home/padraig/tst/ascii /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/ascii
> TARGET                       SOURCE     FSTYPE OPTIONS
> /home/padraig/tst/co\x0atrol /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/co\x0atrol
> TARGET                       SOURCE     FSTYPE OPTIONS
> /home/padraig/tst/back\slash /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/back\slash
> TARGET                       SOURCE     FSTYPE OPTIONS
> /home/padraig/tst/es\x63aped /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/es\x5cx63aped
> TARGET SOURCE     FSTYPE OPTIONS
> 
>        /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/non\xfffffffatf8
> TARGET                         SOURCE     FSTYPE OPTIONS
> /home/padraig/tst/日一二三四五六 /dev/loop1 ext2   rw,relatime,seclabel,errors=continue
> /home/padraig/tst/\xffffffe6\xffffff97...
> 
> So two questions.
> 
> 1. Should the back\slash case be back\x5cslash in both cases?

 back\slash is not \x<xdigit> sequence, so escape is unnecessary

 Note that \\server\path is pretty common for cifs and use \x5c
 for all '\' will make the findmnt output unreadable in many cases.
 IMHO is better to be "smart" and use escape sequences only when it's
 really necessary.

> 2. The nonútf8 one produces an errant new line.
> Also in this case could you fall back to using \x escapes for the whole string?

 Yeah, nonútf8 output seems strange, I'll fix it.


 I'll also update findmnt (and others) man pages to explain when and
 how we use \x escapes. Is there any elegant way how to convert \x
 sequences back to the native strings in shell? Maybe we can add some
 hint to the man pages too.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com