Git Bash: Trying to assign current branch to variable in .bashrc alias script, but variable remains-CodePudding

I am trying to register a script alias in my .bashrc for easy switching from the current branch to master, pulling, switching back to the branch, and rebasing.

Currently, my alias script looks like this:

alias gmm="branch=$(git rev-parse --abbrev-ref HEAD);
echo \"Switching from '$branch' to 'master'\";
git checkout master;
git pull;
echo \"Switching from 'master' to '$branch'\";
git checkout $branch;
git rebase master"

However, the current branch does not seem to be saved to the branch variable, and the command prints the following:

Mai@DESKTOP-M71G3R MINGW64 /c/dev/git/myrepo (testing)
$ gmm
Switching from '' to 'master'
Switched to branch 'master'
Your branch is up to date with 'origin/master'.
Authorized uses only. All activity may be monitored and reported
Already up to date.
Switching from 'master' to ''
Your branch is up to date with 'origin/master'.
Successfully rebased and updated refs/heads/master.

I have already checked that the command itself indeed gets the current branch name:

Mai@DESKTOP-M71G3R MINGW64 /c/dev/git/myrepo (testing)
$ branch=$(git rev-parse --abbrev-ref HEAD)

Mai@DESKTOP-M71G3R MINGW64 /c/dev/git/myrepo (testing)
$ echo $branch
testing

I've spent days googling but I can't figure out where and why the variable assignment fails.

CodePudding user response：

You should use single quotes for alias content as suggested here. When using double quotes, $(git rev-parse --abbrev-ref HEAD) will resolve as early as .bashrc is executed and will probably become empty string. If you use single quotes instead, $(git rev-parse...) will resolve when gmm is run, which means it correctly becomes current branch's name.

alias gmm='branch=$(git rev-parse --abbrev-ref HEAD);
echo "Switching from '\''$branch'\'' to master";
git checkout master;
git pull;
echo "Switching from master to '\''$branch'\'';
git checkout "$branch";
git rebase master'

Preferably I would use bash function instead of alias, which is more convenient.

gmm() {
  local branch=$(git rev-parse --abbrev-ref HEAD);
  echo "Switching from $branch to master";
  git checkout master;
  git pull;
  echo "Switching from master to $branch";
  git checkout "$branch";
  git rebase master
}