Export complete MongoDB as JSON files with one record a line

mongoexportall.sh

#!/bin/bash
#
# mongoexportall [directory [connection-options..]]
#
# This Works is placed under the terms of the Copyright Less License,
# see file COPYRIGHT.CLL.  USE AT OWN RISK, ABSOLUTELY NO WARRANTY.
# (CLL is more free than Public Domain, as it disallows Copyrights.)

OOPS() { { printf 'OOPS:'; printf ' %q' "$@"; printf '\n'; } >&2; exit 23; }

DIR="${1:-export}"
CONN=("${@:2}")

M()
{
mongo --quiet "${CONN[@]}" "$@"
}

Mall()
{
M --eval "[for (a of db.getMongo().getDBNames()) if (a!='local') for (b of db.getMongo().getDB(a).getCollectionNames()) if (b!='system.indexes') (a+'\t'+b)].join('\n')"
}

mkdir "$DIR" || OOPS "$DIR" exists
trap 'rmdir "$DIR" 2>/dev/null' 0

while IFS=$'\t' read -ru6 db coll
do
	mongoexport "${CONN[@]}" -d "$db" -c "$coll" -o "$DIR/$db.${coll//\//--}.json"
done 6< <(Mall)