git_branch.sh

# init
git init

# add files
git add .

# commit files
git commit -m 'add file'

# create branch and check it out
git checkout -b testbranch

# show branches
git branch
                                                                     
# modify file in testbranch
echo "modifiy file in branch" >> test.txt

# commit to testbranch                                                               
git commit -a -m 'modified file'

# switch to master
git checkout master

# merge changes to master
git merge testbranch

# check if your commits are there
git log

# look at the file
cat test.txt
Hallo
modifiy file in branch <- merged change