git pre-commit hook to check whitespace errors

pre-commit

  1 #!/usr/bin/bash                                                                                     
  2                                                                                                     
  3 if git rev-parse --verify HEAD >/dev/null 2>&1                                                      
  4 then                                                                                                
  5     against=HEAD                                                                                    
  6 else                                                                                                
  7     echo "pre-commit: About to create the first commit..."                                          
  8     against=4b825dc642cb6eb9a060e54bf8d69288fbee4904  # magic commit ID for empty commit            
  9 fi                                                                                                  
 10                                                                                                     
 11 if ! git diff-index --check --cached $against                                                       
 12 then                                                                                                
 13     echo "pre-commit: Aborting commit due to whitespace errors"                                     
 14     exit 1                                                                                          
 15 fi                                                                                                  
 16                                                                                                     
 17 exit 0