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kiasari
kiasari

Reputation: 141

Renaming JSON files based on their contents

I have loads of geographical json files with date_geohash.json name format and I have to convert them to date_latitude-longotude.json format. For example I need to convert 2017-03-28_u13hhyn.json to 2017-03-28_N52.76-E1.62.json.   I'm trying to write a bash script to rename these json files using 'rename' and 'jq' (json query) utilities. Using jq I can extract latitude and longitude from the json files.

jq '"\(.latitude)-\(.longitude).json"' 2017-03-28_u13hhyn.json

gives me

“52.768471-1.623297.json"

  However, I don't know how to truncate the latitude and longitude digits and rename the json files.  

 

Upvotes: 1

Views: 818

Answers (2)

kiasari
kiasari

Reputation: 141

Following Andrew's code, I concluded:

#!/bin/bash

for file in *.json; do
  prefix=${file%%_*} 
  latitude=$(jq '.latitude' ${file})
  longitude=$(jq '.longitude' ${file})

  if (( $(echo "$longitude > 0" | bc -l) )); then
    new_name=$(printf "%s_N%.2f-E%.2f.json" ${prefix} ${latitude} ${longitude})
  else
    Longitude=${longitude#-}
    new_name=$(printf "%s_N%.2f-W%.2f.json" ${prefix} ${latitude} ${Longitude})
  fi

  mv ${file} ${new_name}
done;

I'm wondering how can I use one printf instead of two?

Upvotes: 0

Andrew Vickers
Andrew Vickers

Reputation: 2654

It might be better to extract the latitude and longitude into variables, then manipulate into the filename format you want with printf. Then just rename the file. Here's a basic example:

#!/bin/bash

declare    directory="/some/directory/path"
declare    pattern="*_*.json"

cd ${directory}
for file in ${pattern}; do
  prefix=${file%%_*}    # Remove first underscore and everything following.
  latitude=$(jq '.latitude' ${file})
  longitude=$(jq '.longitude' ${file})
  new_name=$(printf "%s_N%.2f-E%.2f.json" ${prefix} ${latitude} ${longitude})
  mv ${file} ${new_name}
done;

Note 1: printf does not truncate the numbers, it rounds them, which is going to give more accurate results.

Note 2: I have hard-coded 'N' and 'E' into the filename, on the assumption that latitude and longitude will be negative for S and W. If this is not the case, there is a little more work required, but the priciple stays the same.

Upvotes: 1

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