A simple Wordpress backup script... it's not perfect, but it'll get the job done for most basic setups.

wp-backup.sh

#!/bin/bash
# MySQL database credentials
DB_USER="" # put your wordpres mysql user name here
DB_PASS='' # put your database password here
DB_NAME="" # put your mysql database name here 
DB_HOST="" # put your mysql host here
# Base path for wordpress files 
WWW_DIR="/var/www/html" # set this to the base path of your wordpress install 

# Set the date format, filename and the directories where your backup files will be placed and which directory will be archived.
BASE_URL="introspectdata.com"
NOW=$(date +"%Y-%m-%d-%H%M")
YEAR=$(date +"%Y")
MONTH=$(date +"%m")
DAY=$(date +"%d")
FILE="$BASE_URL.$NOW.tar"
BACKUP_DIR="/tmp"
DB_FILE="$BASE_URL.$NOW.sql"

# Tar transforms for better archive structure.
WWW_TRANSFORM='s,^"'${WWW_DIR:1:${#WWW_DIR}-1}',html,'
DB_TRANSFORM='s,^tmp,database,'

# Create the archive and the MySQL dump
# note: if you want to exclude specific plugins or other files, you can put additional --exclude statements in the tar command  
tar -cvf $BACKUP_DIR/$FILE --transform $WWW_TRANSFORM --exclude='*/wp-config.php' $WWW_DIR

# mysql dump
echo -e "[mysqldump]\nuser=$DB_USER\npassword='$DB_PASS'" > /tmp/.my.cnf
mysqldump  --defaults-extra-file=/tmp/.my.cnf -h$DB_HOST $DB_NAME > $BACKUP_DIR/$DB_FILE
rm -rf .my.cnf

# Append the dump to the archive, remove the dump and compress the whole archive.
tar --append --file=$BACKUP_DIR/$FILE --transform $DB_TRANSFORM $BACKUP_DIR/$DB_FILE
rm $BACKUP_DIR/$DB_FILE
gzip -9 $BACKUP_DIR/$FILE

# Optionally upload your backup file somewhere like S3... 
# BUCKET_NAME= # name of the bucket to upload to
# aws s3 cp $BACKUP_DIR/$FILE s3://$BUCKET_NAME/$FILE
# Optionally delete the backup file... i.e. if you've uploaded it 
# rm -rf $BACKUP_DIR/$FILE