From Ryan Armstrong's blog, here's how you do it

find . -type d -empty -not -path "./.git/*" -exec touch {}/.gitkeep \; 

• find . -type d (recursively) looks for directories under current path
• -empty filters out directories that already contain something
• -not -path "./.git/*" ensures no files are created inside .git directory
• -exec touch {}/.gitkeep \; creates empty .gitkeep file in each directory matching above criteria

The resulting structure looks like

$ tree -a -I .git . ├── .gitignore ├── README.md ├── pom.xml └── src ├── main │   ├── java │   │   └── .gitkeep │   └── resources │   └── .gitkeep └── test ├── java │   └── .gitkeep └── resources └── .gitkeep 7 directories, 7 files 

From Ryan Armstrong's blog, here's how you do it with GNU find or compatible:

find . -type d -empty -not -path "./.git/*" -exec touch {}/.gitkeep \; 

• find . -type d (recursively) looks for directories under current path
• -empty filters out directories that already contain something
• -not -path "./.git/*" ensures no files are created inside .git directory
• -exec touch {}/.gitkeep \; creates empty .gitkeep file in each directory matching above criteria

The resulting structure looks like

$ tree -a -I .git . ├── .gitignore ├── README.md ├── pom.xml └── src ├── main │   ├── java │   │   └── .gitkeep │   └── resources │   └── .gitkeep └── test ├── java │   └── .gitkeep └── resources └── .gitkeep 7 directories, 7 files 

From Ryan Armstrong's blog, here's how you do it

find . -type d -empty -not -path "./.git/*" -exec touch {}/.gitkeep \; 

• find . -type d (recursilvey) looks for directories under current path
• -empty filters-out intermediate directories
• -not -path "./.git/*" ensures no files are created inside .git directory
• -exec touch {}/.gitkeep \; creates empty .gitkeep file in each directory matching above criteria

The resulting structure looks like

$ tree -a -I .git . ├── .gitignore ├── README.md ├── pom.xml └── src ├── main │   ├── java │   │   └── .gitkeep │   └── resources │   └── .gitkeep └── test ├── java │   └── .gitkeep └── resources └── .gitkeep 7 directories, 7 files 

From Ryan Armstrong's blog, here's how you do it

find . -type d -empty -not -path "./.git/*" -exec touch {}/.gitkeep \; 

• find . -type d (recursively) looks for directories under current path
• -empty filters out directories that already contain something
• -not -path "./.git/*" ensures no files are created inside .git directory
• -exec touch {}/.gitkeep \; creates empty .gitkeep file in each directory matching above criteria

The resulting structure looks like

$ tree -a -I .git . ├── .gitignore ├── README.md ├── pom.xml └── src ├── main │   ├── java │   │   └── .gitkeep │   └── resources │   └── .gitkeep └── test ├── java │   └── .gitkeep └── resources └── .gitkeep 7 directories, 7 files