On Tue, 15 Aug 2017 02:11:37 -0400 chris...@zoulas.com (Christos
Zoulas) wrote:
> On Aug 14, 10:50am, idler...@fastmail.fm ("Ian D. Leroux") wrote:
> -- Subject: Re: Fixing swap1_stop
>
> | Any preferences for a conveniently-parseable format? My first
> | instinct is to simply drop the spacer words ("on", "type"),
> | systematically shquote() the device and mount-point and
> | space-separate the flags. That would look like:
> |
> | '/dev/wd0a' '/' ffs synchronous local
> | 'tmpfs' '/var/shm' tmpfs nosuid local
>
> The flags can be complicated (see source code)
>
> | That's directly parseable in shell (first three fields are device,
> | mount point and fstype, any leftovers are individual flags) and
> | doesn't require the design of another date-style formatting
> | language. Are there other, better ideas?
>
> We can specify a format with % escapes for each field...
I was hoping to avoid being guilty of yet another printf-style
mini-language. But I don't currently have any better ideas, so let's
work this one out. The filesystem, mount point and device get an
escape each (say %f, %m and %d respectively). How should the flags be
handled? One escape for the whole comma-separate flag string (as in
the current output)? That's easy to implement and manageable to work
with, since the flag names are well-behaved single words that are not
under user control, so they could be parsed with shell globs, something
like:
FLAGS=$(mount -F '%F')
case $FLAGS in
*local*) # do local filesystem stuff
;;
*nosuid*)
;;
esac
Alternatively, each flag could get its own % escape (perhaps one that
expands to "yes" or "no"), but that makes it harder to write a format
string that reproduces the default output.
I don't currently have a use for extracting the flag information (since
my immediate interest is just in getting a reliable mount point name),
so I'm not sure which format is most useful in practice.
--
IDL
