gitignore binary files that have no extension

Question

How can binary files be ignored in git using the .gitignore file?

Example:

$ g++ hello.c -o hello

The

Answer 1

# Ignore all
*

# Unignore all with extensions
!*.*

# Unignore all dirs
!*/

### Above combination will ignore all files without extension ###

# Ignore files with extension `.class` & `.sm`
*.class
*.sm

# Ignore `bin` dir
bin/
# or
*/bin/*

# Unignore all `.jar` in `bin` dir
!*/bin/*.jar

# Ignore all `library.jar` in `bin` dir
*/bin/library.jar

# Ignore a file with extension
relative/path/to/dir/filename.extension

# Ignore a file without extension
relative/path/to/dir/anotherfile