At work today I had to run a lot of SQL files which had --//@UNDO followed by SQL commands to rollback the transactions carried out at the top of the file. This is standard for SQL migration files, However MySQL server errors out when it encounters this. I used a quick shell script to remove all the --//@UNDO and all the SQL commands which followed it.
for i in *; do echo "Processing" $i; sed '/\-\-\/\/@UNDO/,$d' $i > /tmp/$i; done;
The above line will delete all lines starting from --//@UNDO until the end of file. The modified contents are then written to /tmp. The original file remains unchanged.