How to use git revert?

git-revert-sample

git-revert $ git init

git-revert (master) $ touch 1.txt
git-revert (master) $ touch 2.txt
git-revert (master) $ git add .
git-revert (master) $ git commit -am "wanted commit 1"
[master (root-commit) 80395aa] wanted commit 1
 2 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 1.txt
 create mode 100644 2.txt


git-revert (master) $ touch 3.txt
git-revert (master) $ touch 4.txt
git-revert (master) $ git add .
git-revert (master) $ git commit -am "wanted commit 2"
[master b54ab04] wanted commit 2
 2 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 3.txt
 create mode 100644 4.txt

git-revert (master) $ touch 5.txt 6.txt
git-revert (master) $ git add .
git-revert (master) $ git commit -am "unwanted commit 1"
[master 30a89ba] unwanted commit 1
 2 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 5.txt
 create mode 100644 6.txt

git-revert (master) $ touch 7.txt 8.txt
git-revert (master) $ git add .
git-revert (master) $ git commit -am "unwanted commit HEAD"
[master 4501a98] wanted commit 3
 2 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 7.txt
 create mode 100644 8.txt

git-revert (master) $ git lg
4501a989fd918ab13b5ddc8a417f7fe37f379caf wanted commit 3
30a89ba605aa38c050a520b7312063f4afcfe947 unwanted commit 1
b54ab04e6c57209b469d6b60b0dc3de9c2042d0b wanted commit 2
80395aa942b5e1d50087e23487ba5b8778fc66c4 wanted commit 1
git-revert (master) $ ls
1.txt	2.txt	3.txt	4.txt	5.txt	6.txt	7.txt	8.txt

# Reverting last commit
git-revert (master) $ git revert HEAD
[master 2db3742] last commit - Revert "unwanted commit HEAD"
 2 files changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 7.txt
 delete mode 100644 8.txt

git-revert (master) $ git lg
2db3742af69b09c211e96b1b99127de6c242fe48 last commit - Revert "unwanted commit HEAD"
4501a989fd918ab13b5ddc8a417f7fe37f379caf unwanted commit HEAD
30a89ba605aa38c050a520b7312063f4afcfe947 unwanted commit 1
b54ab04e6c57209b469d6b60b0dc3de9c2042d0b wanted commit 2
80395aa942b5e1d50087e23487ba5b8778fc66c4 wanted commit 1

git-revert (master) $ git revert 30a89ba605aa38c050a520b7312063f4afcfe947
[master caf20a6] Revert "unwanted commit 1"
 2 files changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 5.txt
 delete mode 100644 6.txt

git-revert (master) $ git lg
caf20a62b4f2b39f4c58bf8a70d98226c936b44f Revert "unwanted commit 1"
2db3742af69b09c211e96b1b99127de6c242fe48 last commit - Revert "unwanted commit HEAD"
4501a989fd918ab13b5ddc8a417f7fe37f379caf unwanted commit HEAD
30a89ba605aa38c050a520b7312063f4afcfe947 unwanted commit 1
b54ab04e6c57209b469d6b60b0dc3de9c2042d0b wanted commit 2
80395aa942b5e1d50087e23487ba5b8778fc66c4 wanted commit 1
git-revert (master) $