How To Use AWK To Simplify Scripting: Multi-Database Backup Example

AWK is an extremely versatile and powerful language for processing files and text data. Often you can use awk to perform complex tasks on Unix / Linux / Mac OS command line which would otherwise take a full-fledged programming effort. AWK is great for log processing, creating custom scripts which will then be executed and more. For example I wanted to create a backup of all of my MySQL databases, each to a separate file after compressing them with gzip (maximum compression). I already created a list of databases on my MySQL server is a file named databases (how original!). Here is the awk script which processes the file and creates another file (named database_backup) which contains commands to backup all the databases as specified above.

awk '{print "mysqldump -u root -p --opt",$1,"|gzip -9 >",$1 ".sql.gz"}' < databases > database_backup

I actually use a slightly modified script where I specify the password after -p so I don’t have to type it every time and also enables me to run this as a cron job.