Export all tables including headers in a postgres database to a set of CSV files

psql_to_csv.sh

#!/bin/bash

DB_NAME="$USER"
DBMS_SHELL="psql"
DBMS_USER="postgres"

#if [ "$1" = '--help' ]; then
if [[ ( "$1" == '--help' ) || ( "$1" == '-h' ) ]]; then
	echo "usage: $0 [DB_NAME] [DBMS_SHELL]"
	echo "default DB_NAME is your username"
	echo "default DBMS_SHELL is 'psql'"
	echo "default DBMS_USER is 'postgres'"
	exit 0
fi

if [ -n "$1" ]
then DB_NAME="$1"
fi
if [ -n "$2" ]
then DBMS_SHELL="$2"
fi
if [ -n "$3" ]
then DBMS_USER="$3"
fi

alias echo='>&2 echo'

mkdir -p "$DB_NAME"
echo "Fetching table list ..."
$DBMS_SHELL "$DB_NAME" -U $DBMS_USER -c "copy (select table_name from information_schema.tables where table_schema='public') to STDOUT;" > "$DB_NAME/tables.txt"
dbms_success=$?
if ! [ $dbms_success ]
then exit 4
fi

echo "Fetching tables ..."
readarray tables < "$DB_NAME/tables.txt"
for t in ${tables[*]}; do
	$DBMS_SHELL -d "$DB_NAME" -U $DBMS_USER -c "copy (select * from $t) to STDOUT with delimiter ',' CSV HEADER;" > "$DB_NAME/$t.csv"
done

This was very useful !! Thank you.

Thanks. I'm really interesting to use this script but during execution, I got below. How to make it work?
Fetching table list ...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = "en_NZ:en",
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Fetching tables ...

I have error like this

How can I fix it