Submodule

Updating a submodule (git version >= 1.8.2)

Here is how to update the existing git submodule located in source/css/pygments-css.

git submodule update --remote --merge source/css/pygments-css

To update all the submodules in a row, do not specify any module name.

Source

Update a Submodule (git version <= 1.8.2)

Here is how to update the existing git submodule located in source/css/pygments-css.

git submodule  
  232c5d1112e05011ccd97e6172ea2d23ec0f2440 source/css/pygments-css (heads/master)

• Go to the module directory

cd source/css/pygments-css

You can note the git commands we run here are connected to the submodule's remote.

git remote -v
  origin	git@github.com:ebouchut/pygments-css.git (fetch)
  origin	git@github.com:ebouchut/pygments-css.git (push) 

• Pull the latest modifications from the branch (master in my case)

git pull origin master

  From github.com:ebouchut/pygments-css
   * branch            master     -> FETCH_HEAD
  Updating 232c5d1..458696b
  Fast-forward
   README.rst   |   4 ++--
   autumn.css   | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------------------
   borland.css  |  92 ++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------
   bw.css       |  68 ++++++++++++++++++++++++++++++++++----------------------------------
   colorful.css | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   default.css  | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------------------------------------------
   emacs.css    | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   friendly.css | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   fruity.css   | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------------
   github.css   | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   manni.css    | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   monokai.css  | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------
   murphy.css   | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------------------------
   native.css   | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------------
   pastie.css   | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------------------------------------------
   perldoc.css  | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------------------
   tango.css    | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------------
   trac.css     | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------------------------------------------
   vim.css      | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------------
   vs.css       |  66 +++++++++++++++++++++++++++++++++---------------------------------
 zenburn.css  |   2 +-
   21 files changed, 1118 insertions(+), 1118 deletions(-)

• Go to the main project (the one containing the submodule)

cd ../../..           # Back to the main project

• Commit the updated submodule

git add source/css/pygments-css   # Add the updated module
git commit -m "Update submodule pygments-css to the latest version"

• Push upstream

git push

Source