Disable All Jenkins Jobs from jobs folder.

disablejobs.sh

#!/bin/bash

# Check to see if your jenkins home is in
# /var/lib/jenkins. If it isn't, then modify the script
# This will traverse through all your jobs, and disable them.

cd /var/lib/jenkins/jobs

for d in */ ; do   
    cd "$d"
    sudo sed -i 's/disabled>false/disabled>true/' config.xml
    cd ../
done

# Restart Jenkins just to be safe.
sudo /etc/init.d/jenkins restart