How to bulk change MySQL Triggers DEFINER

Without using --add-drop-trigger option:

currentUserDefiner='root'
currentHostDefiner='localhost'
newUserDefiner='user'
newHostDefiner='localhost'
db='myDb'
mysqldump -u root --triggers --no-create-info --no-data --no-create-db --skip-opt $db \
| perl -0777 -pe 's/(\n\/\*.+?50003 TRIGGER `([^`]+)`)/\nDROP TRIGGER \2;\1/g' \
| perl -0777 -pe 's/(DEFINER[^`]+)'$currentUserDefiner'(`@`)'$currentHostDefiner'/\1'$newUserDefiner'\2'$newHostDefiner'/gi' \
> out.sql
mysql -u root < out.sql

One way to do it:

1) Dump trigger definitions into a file

# mysqldump -uroot -p --triggers --add-drop-trigger --no-create-info \
      --no-data --no-create-db --skip-opt test > /tmp/triggers.sql

2) Open triggers.sql file in your favorite editor and use Find and Replace feature to change DEFINERs. Save updated file.

3) Recreate triggers from the file

# mysql < triggers.sql