Write a simple bash shell script to run on centos 7.1 to delete files once a size-threshold is reached

Write a simple bash shell script to run on centos 7.1 to delete files once a size-threshold is reached. This is quite simple. We have a Centos 7.1 server. One of the directories gets filled up a few times a day. We believe it is a problem created by one of our applications. However, until we can solve the basic problem, we are looking for a short-cut solution. We need a script that we can run on our server a. on the command prompt. By the way , the script can have root access. b. schedule it as a cron to run periodically. The script should 1. check the size of the drive. 2. If the size if above 85% of its capacity, then it should simple delete all files in a particular folder in that drive (lets called it the TARGERFOLDER) of the following the filetypes: a. Files with extension of .MAD b. Files with extession of .MAI You can hard-code the following: 1. TARGETFOLDER 2. TARGETSIZEPERCENT You may have these as variables in the beginning of the script so that we can go in modify them as and when necessary.