# watchexec > Run arbitrary commands when files change. > More information: . - Call `ls -la` when any file in the current directory changes: `watchexec {{ls -la}}` - Run `make` when any JavaScript, CSS and HTML file in the current directory changes: `watchexec {{[-e|--exts]}} {{js,css,html}} make` - Run `make` when any file in the `lib` or `src` directory changes: `watchexec {{[-w|--watch]}} {{lib}} {{[-w|--watch]}} {{src}} {{make}}` - Call/restart `my_server` when any file in the current directory changes, sending `SIGKILL` to stop the child process: `watchexec {{[-r|--restart]}} --stop-signal {{SIGKILL}} {{my_server}}` - Restart the execution of a command when any Java source file in the current directory changes, sending `SIGKILL` and only checking for updates every `n`ms: `watchexec {{[-r|--restart]}} --stop-signal {{SIGKILL}} --poll {{10000}} {{[-e|--exts]}} {{java}} {{command}}`