Restoring an old post from an old blog about using traps and signals in bash.

It is common to launch commands of this type: search for a series of files and, once found, write a certain string in each of them. A practical example would be to search for the scheduler files for disk devices and write in them the name of the desired elevator.

Sometimes we face certain limitations when writing shell scripts when handling strings, and we often forget that bash has a lot of strings operators.