[gradsusr] get output from shell command

[Charles Seman]

Bernd,

I'm not sure how GrADS runs in parallel?

Do you start GrADS 17 different times?  If so, if this would help, 
perhaps you could give each of the "sysdate.dat" files a name using the 
GrADS process ID's as follows (to illustrate technique):
ga-> echo `ps |grep grads`
Unknown command: echo
ga-> ! echo `ps |grep grads`
19846 pts/3 00:00:00 grads
ga-> ! echo `ps |grep grads | cut -f1`
19846 pts/3 00:00:00 grads
ga-> ! echo `ps |grep grads | cut -f1 -d' '`
19846

...after quiting GrADS and restarting:
ga-> !touch sysdate.`ps |grep grads | cut -f1 -d' '`
ga-> !ls sysdate.*
sysdate.19919

Note, you may need to do additional "bookkeeping" to know which 
"sysdate.*" file to use when...

If the above does not seem workable, another possibility would be to 
"append" the information to a single "sysdate.dat" file using ">>":

'!date >> sysdate.dat'


Note, you may need to initialize "sysdate.dat" like:
'!touch sysdate.dat'
before doing the first "append" using ">>"...

Then, keep track of which line in the file corresponds to which of the 
17 GrADS shells... I'm not sure how you are initiating 17 GrADS shells, 
or whether it is possible to know the order of how the GrADS shells are 
started and/or the order in which each GrADS shell writes the "date" 
into the "sysdate.dat" file, etc...

Hope this helps,
Chuck


Becker, Bernd wrote:
>  
>
> Chuck, 
> nice solution,
> but if you have 17 grads shells running in parallel, eventually
> one of them may overwrite sysdate.dat and that would be bad. 
>
> Thanks!
> Bernd
> --
> Bernd Becker   Climate Impacts Product Development
> Met Office Hadley Centre    FitzRoy Road  Exeter   Devon EX1 3PB  United
> Kingdom
> Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050
> E-mail:bernd.becker at metoffice.gov.uk -
> http://www.metoffice.gov.uk/research/our-scientists/seasonal-to-decadal/
> bernd-becker
>
>
> -----Original Message-----
> From: gradsusr-bounces at gradsusr.org
> [mailto:gradsusr-bounces at gradsusr.org] On Behalf Of Charles Seman
> Sent: 16 March 2011 18:15
> To: GrADS Users Forum
> Subject: Re: [gradsusr] get output from shell command
>
> Bernd,
>
> Arindam Chakraborty sent a technique to the Listserv (email exchange
> attached):
>
> '!date > sysdate.dat'
>  d = read('sysdate.dat')
>  d1 = sublin(d,2)
>  say d1
>
>
>
> Hope this helps,
> Chuck
>
> Becker, Bernd wrote:
>   
>> Hello,
>>
>> how do I get the output from shell command "date"
>> into the grads shell?
>>
>> '!date'
>> res  = result
>> say rc    res
>> res=sublin(rc,2)
>> say rc    res
>> say subwrd(res   ,2)
>>
>> doesn't do it.
>>
>> Te following does, but with caveats:
>> I got this far: 
>>
>> '!date -d 'fxdate' +%b > ./erp2' 
>> record2=read('./erp2')
>> mon=sublin(record2,2)
>>
>> but it is unsave if multiple processes run in parallel and overwrite 
>> erp2. Not good enough.
>>
>> many thanks!
>>
>> Bernd.
>>
>> --
>> Bernd Becker   Climate Impacts Product Development
>> Met Office Hadley Centre    FitzRoy Road  Exeter   Devon EX1 3PB
>>     
> United
>   
>> Kingdom
>> Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050 
>> E-mail:bernd.becker at metoffice.gov.uk - 
>> http://www.metoffice.gov.uk/research/our-scientists/seasonal-to-decada
>> l/
>> bernd-becker
>>
>>
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>   
>>     
>
>   

-- 

Please note that Charles.Seman at noaa.gov should be considered my NOAA
email address, not cjs at gfdl.noaa.gov.

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