git commit -m vs. git commit -am

Question

Seems easy but I just don't get it. I am in the root of my application.

Here is my workflow.

git add . git commit -m "added a new feature some files changed" git push heroku master 

This usually works. All my changes are pushed.

But sometimes I have a file that I change but when I push to Heroku the changes are not there for THAT ONE FILE... but for most of the files the changes are there...

But if I do

git add . git commit -am "added a new feature some files changed" git push heroku master 

Everything (all changes) are pushed to Heroku

Answer 1

From the docs:

git commit -a automatically stage all tracked, modified files before the commit If you think the git add stage of the workflow is too cumbersome, Git allows you to skip that part with the -a option. This basically tells Git to run git add on any file that is "tracked" - that is, any file that was in your last commit and has been modified. This allows you to do a more Subversion style workflow if you want, simply editing files and then running git commit -a when you want to snapshot everything that has been changed. You still need to run git add to start tracking new files, though, just like Subversion.

Using the option -am allows you to add and create a message for the commit in one command.