How to verify the current git branch in a Windows BAT file

Question

I'm trying to figure out how to verify that the user is on the correct branch before running some commands in my BAT file.

What's the best way to perform this kind of check...

IF (on "master" git branch) THEN
   ...
ELSE
   ...

Prim

Answer 1

Use the following to return only the current branch:

git rev-parse --abbrev-ref HEAD

FINDSTR can use a regular expression to match on the branch name:

FINDSTR /r /c:"^master$" 

This works except that git rev-parse uses LF instead of CRLF for line endings, while the end of line match in the regex is looking for CR. Adding FIND /v "" to change the LF to CRLF results in this:

git rev-parse --abbrev-ref HEAD | find /v "" | findstr /r /c:"^master$" > NUL & IF ERRORLEVEL 1 (
  ECHO I am NOT on master
) ELSE (
  ECHO I am on master
)

This will match the branch "master", but not a branch name containing the word master.

Tartuffe

Awesome! Thanks for the detailed answer. Yours will be more accurate than my answer, being able to use regex. 👍 – Prim

git branch --show-current will provide the same result as git rev-parse --abbrev-ref HEAD – Reverential

Answer 2

You can determine what branch you are on using the git branch command so we'll use the output of that for our check. The asterisk will mark the current branch, like so:

D:\>git branch
  master
* staging

We can pipe this output to the find command and then to an IF statement:

git branch | find "* master" > NUL & IF ERRORLEVEL 1 (
    ECHO I am NOT on master
) ELSE (
    ECHO I am on master
)

The > NUL just silences the output of the find.
find will trigger an ERRORLEVEL 1 if it cannot find the string anywhere in the output.

Prim

Ooh good tip @mrexodia. Good branch naming techniques will avoid that, but I wonder if there's a way to suit those edge cases. – Prim

I wanted to use this to determine if something is a pull request in my build server to trigger a special build process without signing etc. That use case could be common so I warned people about this exploit :) – Littoral