Jenkins run without build - jenkins

Question

I have made a simple program that needs to be executed once in every hour. I've set in Jenkins to run every hour and run shell commands at post step of the build.
The thing is that it needs to build only when the code is changed on GIT. If nothing has changed, I'd just like to run the post steps without the new build.
Is there any way to take care of this? I just can't find any plugins to take care of this.
git change -> build -> run post step.
git not change -> build X -> run post step every hour
Thanks in advance.
-edit-
This simple program is currently running on my Jenkins every hour as below.
trigger(every hour) -> get code from Github -> build -> run post step(executing three shell commands)
But! I want to change to
trigger(every hour) -> get code from Github -> build -> run post step(executing three shell commands)
+
trigger(when Github code changes) -> get code from Github -> build -> run post step(executing three shell commands)

Answer 1

If I understand your requirements correctly, you can set your job to build on a Git push to master (or whatever branch) using a Git hook while also keeping the hourly build and add a check in your code for the build cause. Something like (this is inside an execute shell step):
if [ $BUILD_CAUSE != 'TIMERTRIGGER' ]; then
build your code
fi
execute 3 commands
That way builds triggered by the timer will skip the code build but manual or hook triggers will not.
If you are using pipeline you can use currentBuild.rawBuild.getCauses()[0].getShortDescription().contains('text identifying git trigger') for similar results.
Edit: an alternative solution using the Conditional BuildStep plugin.
Add a Conditional Step (single) with the trigger as build cause SCM Trigger as the first step on the build and add a second build step to run the shell commands. See attached screenshot (in the image the Post build Actions tab is highlighted but this is done in the Build section).