How to provide a prepared git commit message?

Question

By convention I create my story branches in git to include Jira issue ids in them, e.g. FOO-1001. I have a script to do that for me. Now, I have prepared another script that fet

Answer 1

There's also -F:

   -F <file>, --file=<file>
       Take the commit message from the given file. Use - to read the message from the standard input.

Answer 2

The commit command has an option for reading a commit message from a template:

 -t <file>, --template=<file>
       When editing the commit message, start the editor with the contents
       in the given file. The commit.template configuration variable is often
       used to give this option implicitly to the command. This mechanism can
       be used by projects that want to guide participants with some hints on
       what to write in the message in what order. If the user exits the editor
       without editing the message, the commit is aborted. This has no effect
       when a message is given by other means, e.g. with the -m or -F options.