[GRASS-user] for looping using attribute levels of a vector

[Alex Mandel]

Milton Cezar Ribeiro wrote:
> Dear R-gurus,
> 
> I have a vector file which have several attributes.
> One of the columns have values that repeat like
> the name of city. So, I would like to do some
> steps for each level of the column of interest.
> 
> Just supose that I have CityA, CityB, CityC
> 
> I would like to use this strings on a for loop.
> 
> Following suggestions by Hamish, I addapted the
> following temptative code:
> 
> 
> for MAP in `v.db.select map=mymap column=city` ; do
>   echo my steps...
> done
> 
> But when the first entry on the looping is the name
> of the field (City), and when the city have white
> space like "Los Angeles", each word are used
> as different entry of MAP variable of the "for" looping.
> 
> My questions are:
> 1. How can I bypass the problem of "v.db.select" return
> the name of column as first entry
> 2. How can I bypass the problem of white space for
> city names?
> 
> Best wishes
> 
> miltinho astronauta
> brazil
> 
> 
> 
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1. Looking at the docs -c drops the column name.

2. Hmm, you probably need to find a way to encapsulate each line in
quotes for the loop reads each string or put a delimiter in that you can
parse. maybe try vs="," to add a character.

http://grass.itc.it/grass63/manuals/html63_user/v.db.select.html

Alex