View a short summary of Git commits

One of the most common things you might need to do when working with Git is to view a short summary of your commits. While git log is the go-to command for this, it can be a bit verbose at times. Luckily, it provides a plethora of options to help you customize its output.
One of these is --oneline, which is actually a shorthand for --pretty=oneline --abbrev-commit. It prints a short summary of all commits, with each commit being printed on a single line.
Notice the short, 7-character commit identifiers. This is because of the --abbrev-commit option, which abbreviates the commit SHA-1 checksum to 7 characters. This shorter string is enough to uniquely identify a commit.
Other options can be used in conjunction with --oneline to further customize the output. For example, you can use --no-merges to exclude merge commits from the output.

git log --oneline
# d540ba1 Merge network bug fix
# 3050fc0 Fix network bug
# c191f90 Initial commit

Notice the short, 7-character commit identifiers. This is because of the --abbrev-commit option, which abbreviates the commit SHA-1 checksum to 7 characters. This shorter string is enough to uniquely identify a commit.
Other options can be used in conjunction with --oneline to further customize the output. For example, you can use --no-merges to exclude merge commits from the output.

From 30-seconds-of-code: view-commits-summary