Shell process for WordPress media regeneration in batches

wp-media-regenerate-batch.sh

# ============================================================ 
# Shell process to regenerate WordPress thumbnails in batches
# Author: Mauricio Gelves <mg@maugelves.com>
# Twitter: @maugelves
# Website: maugelves.com
# Version: 0.1
# Syntax: wp-media-regenerate-batch.sh  <options>
#
#	Options:	-u 	Database username.
#			-d 	Database name.
#			-p 	Database password.
#			-s 	<optional> Thumbnail Size: Name of the image size to regenerate.
#			-e 	<optional> Pause every X iteration, by default every 10 regenerations.
#			-t 	<optional> Pause time, by default every 10 seconds.
# ============================================================



# === VARIABLES

	# Variables for images ID's
	ID_NEXT=""
	ID_TO=""

	# database credentials
	DB_USER=""
	DB_PASS=""
	DB_DATABASE=""

	# pause variables
	PAUSE_EVERY_X_ITERATION=10 # default 10 times
	PAUSE_TIME=10 # default 5 seconds

	# Thumbnails variables
	THUMB_SIZE=""

	# Other variables
	COUNTER=1

# === END VARIABLES




# RETRIEVE ARGUMENTS
while getopts u:d:p:s:e:t: option
do
case "${option}"
in
e) PAUSE_EVERY_X_ITERATION=${OPTARG};;
u) DB_USER=${OPTARG};;
p) DB_PASS=${OPTARG};;
d) DB_DATABASE=${OPTARG};;
s) THUMB_SIZE=${OPTARG};;
t) PAUSE_TIME=${OPTARG};;
esac
done




# VALIDATE ARGUMENTS
if [ "$DB_USER" == "" ] || [ "$DB_PASS" == "" ] || [ "$DB_DATABASE" == "" ]
	then
		echo "The parameters -u, -p and -d are mandatories"
fi


# RETRIEVE THE MIN AND MAX ID FROM ALL THE MEDIAS
ID_NEXT=$(mysql $DB_DATABASE -u $DB_USER -p$DB_PASS -se "SELECT MIN(ID) FROM wp_posts WHERE post_type='attachment'")
ID_TO=$(mysql $DB_DATABASE -u $DB_USER -p$DB_PASS -se "SELECT MAX(ID) FROM wp_posts WHERE post_type='attachment'")

# LOOP THE IMAGES
while (( $ID_NEXT <= $ID_TO ))

	do

		# REGENERATE THE THUMBNAIL USING WP CLI
		if [ "$THUMB_SIZE" == "" ]
		then

			wp media regenerate $ID_NEXT

		else

			wp media regenerate $ID_NEXT --image_size=$THUMB_SIZE

		fi


		# MANAGE THE PAUSE BETWEEN THE REGENERATIONS
		if (( COUNTER == PAUSE_EVERY_X_ITERATION ))
		then

			echo "Sleeping $PAUSE_TIME seconds"
			sleep $PAUSE_TIME

			# RESET THE COUNTER
			COUNTER=0

		else

			# INCRESE THE COUNTER
			COUNTER=$((COUNTER + 1))

		fi

		# GET THE NEXT IMAGE ID TO REGENERATE
		ID_NEXT=$(mysql $DB_DATABASE -u $DB_USER -p$DB_PASS -se "SELECT ID FROM wp_posts WHERE post_type='attachment' AND ID > $ID_NEXT LIMIT 1")
		
	done