Re: string parsing vs hddtemp question

[Andrew Starks <andrew.starks@...>]

On Mar 17, 2013, at 19:24, Laurent Faillie <l_faillie@yahoo.com> wrote:

> Hello,
>
> A question related to file parsing that drive me nut :(
>
> hddtemp is a tool that is monitoring disk temperature.
>
> With only 1 disk, it expose following string :
>    "|/dev/sda|WDC WD5000AAKB-00H8A0|29|C|"
>
> and I've been successfully able to parse it with following code :
>
>    local mnt,tp,temp,unit = string.match( s,
> "|(/dev/%a+)|(%a.+)|(%d+)|(%a)")
>
> But with more disk, the string become :
>    "|/dev/sda|IBM-ESXSDTN073C1UCDY10F|28|C||/dev/sdb|WDC
> WD3200AAJB-00J3A0|43|C||/dev/sdc|Maxtor
> 34098H4|UNK|*||/dev/sdd|???|ERR|*||/dev/sde|???|ERR|*|"
>
> where sda and sdb are disk whom the temperature can be requested.
> sdc is present on the system but it doesn't support temperature query
> (too old).
> sdd and sde aren't present at the moment.
>
> I would like to iterate against disk exposing their temperature (other
> can be ignored) but
>    for mnt,tp,temp,unit in s:gmatch("|(/dev/%a+)|(%a.+)|(%d+)|(%a)|") do
>        print(mnt, tp)
>    end
> miserably fails
>    /dev/sda    IBM-ESXSDTN073C1UCDY10F|28|C||/dev/sdb|WDC WD3200AAJB-00J3A0
>    nil
> so it is confused when reading first disk name.
>
> Any idea to parse such strings, being able to iterate b/w each disks
> whatever the string contains 1 or more disks ?
>
> Thanks
>
> Laurent
>
> ps: I've been able to get the information by iterating against each
> field using "([^|]*)" and then counting next fields to rebuild the
> structure. But I'm looking for a more efficient solution
>
>

The way you're doing it is fine and I think the way you're doing it is
fine. Perhaps just making the pipe ?

I didn't check this. The thrust of my post is really about making this
an opportunity to check lpeg out.

dev = (P"|"^-1 * "/dev/" Ct(alpha)^1 * P"|") -- etc.

--Andrew