git - uncommiting last commit

--soft : uncommit all changes and move back to stage state

Create a new file, stage it (add), commit it and do soft reset HEAD^

$ git branch
* master

$ git checkout -b a_branch
Switched to a new branch 'a_branch'

$ git log --graph --decorate --oneline -n3
* 3d1bb52 (HEAD, master, a_branch) Noh has build ship
* bb7ebab this is john sermon

$ cal 2013 > a_test_file.txt

$ git status
# On branch a_branch
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#       a_test_file.txt

$ git add a_test_file.txt

$ git status
# On branch a_branch
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#       new file:   a_test_file.txt
#

$ git commit -m"a new change commited in a_test_file.txt"
[a_branch c1a194c] a new change commited in a_test_file.txt
 1 files changed, 35 insertions(+), 0 deletions(-)
 create mode 100644 a_test_file.txt

$ git log --graph --decorate --oneline -n3
* c1a194c (HEAD, a_branch) a new change commited in a_test_file.txt
* 3d1bb52 (master) Noh has build ship
* bb7ebab this is john sermon

$ git reset --soft HEAD^

$ git log --graph --decorate --oneline -n3
* 3d1bb52 (HEAD, master, a_branch) Noh has build ship
* bb7ebab this is john sermon


$ git status
# On branch a_branch
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#       new file:   a_test_file.txt
#

--hard : discard all changes permanently ! 

All new files will be deleted and modification to all file will disappear (you cannot recover !)

Commit newly created import file and do --hard reset to make your life hell !

$ git commit -m"a new change commited in a_test_file.txt"
[a_branch 8a59c62] a new change commited in a_test_file.txt
 1 files changed, 35 insertions(+), 0 deletions(-)
 create mode 100644 a_test_file.txt

$ git log --graph --decorate --oneline -n3
* 8a59c62 (HEAD, a_branch) a new change commited in a_test_file.txt
* 3d1bb52 (master) Noh has build ship
* bb7ebab this is john sermon

$ git reset --hard HEAD^
HEAD is now at 3d1bb52 Noh has build ship
$ git log --graph --decorate --oneline -n3
* 3d1bb52 (HEAD, master, a_branch) Noh has build ship
* bb7ebab this is john sermon


$ git status
# On branch a_branch
nothing to commit (working directory clean

You file has been permanently deleted by Mr   --hard !