Is there a way to pretty print MongoDB shell output to a file

Question

Specifically  I want to print the results of a mongodb find   to a file  The JSON object is too large so I m unable to view the entire object with the shell window size

User · Accepted Answer

The shell provides some nice but hidden features because it's an interactive environment.

When you run commands from a javascript file via mongo commands.js you won't get quite identical behavior.

There are two ways around this.

(1) fake out the shell and make it think you are in interactive mode

$ mongo dbname << EOF > output.json
db.collection.find().pretty()
EOF

or
(2) use Javascript to translate the result of a find() into a printable JSON

mongo dbname command.js > output.json

where command.js contains this (or its equivalent):

printjson( db.collection.find().toArray() )

This will pretty print the array of results, including [ ] - if you don't want that you can iterate over the array and printjson() each element.

By the way if you are running just a single Javascript statement you don't have to put it in a file and instead you can use:

$ mongo --quiet dbname --eval 'printjson(db.collection.find().toArray())' > output.json

User · Answer

Just put the commands you want to run into a file  then pass it to the shell along with the database name and redirect the output to a file   So  if your find command is in find js and your database is foo  it would look like this     mongo foo find js  gt  gt  out json

User · Answer

Using print and JSON stringify you can simply produce a valid JSON result  Use --quiet flag to filter shell noise from the output  Use --norc flag to avoid  mongorc js evaluation   I had to do it because of  a pretty-formatter that I use  which produces invalid JSON output  Use DBQuery shellBatchSize     replacing   with the limit of the actual result to avoid paging   And finally  use tee to pipe the terminal output to a file      Shell  mongo --quiet --norc   query js   tee   my output json     query js  DBQuery shellBatchSize   2000  function toPrint data      print JSON stringify data  null  2       toPrint    db getCollection  myCollection   find   toArray        Hope this helps

User · Answer

I managed to save result with writeFile   function    gt  writeFile   home pahan output txt   tojson db myCollection find   toArray       Mongo shell version was 4 0 9

User · Answer

you can use this command to acheive it   mongo admin -u  lt userName gt  -p  lt password gt  --quiet --eval  cursor   rs status    printjson cursor    gt  output json

User · Answer

Also there is mongoexport for that  but I m not sure since which version it is available   Example   mongoexport -d dbname -c collection --jsonArray --pretty --quiet --out output json

User · Answer

Put your query  e g  db someCollection find   pretty    to a javascript file  let s say query js  Then run it in your operating system s shell using command   mongo yourDb  lt  query js  gt  outputFile  Query result will be in the file named  outputFile     By default Mongo prints out first 20 documents IIRC  If you want more you can define new value to batch size in Mongo shell  e g    DBQuery shellBatchSize   100

User · Answer

As answer by Neodan mongoexport is quite useful with -q option for query  It also convert ObjectId to standard format of JSON   oid   E g   mongoexport -d yourdb -c yourcol --jsonArray --pretty -q    field    filter value    -o output json

User · Answer

Using this answer from Asya Kamsky  I wrote a one-line bat script for Windows  The line looks like this   mongo --quiet  1 --eval  printjson db  2 find   toArray      gt  output json  Then one can run it   exportToJson bat DbName CollectionName

User · Answer

Since you are doing this on a terminal and just want to inspect a record in a sane way  you can use a trick like this   mongo   tee somefile   Use the session as normal - db collection find   pretty   or whatever you need to do  ignore the long output  and exit   A transcript of your session will be in the file tee wrote to   Be mindful that the output might contain escape sequences and other garbage due to the mongo shell expecting an interactive session   less handles these gracefully

[javascript] Is there a way to 'pretty' print MongoDB shell output to a file?

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