Wat
[fsnotify] A cross-platform File Watcher that runs specific tasks when specific files are added, changed or deleted
Install / Use
/learn @raphamorim/WatREADME
wat
Fast File Watcher
Run specific tasks when specific files are added, changed or deleted
Usage
Install by doing:
go get -u github.com/raphamorim/wat
Then simply run:
wat <path> <command>
Example using date command:
wat src/ date
Returns for every file update inside src folder:
Waiting...
Sat Oct 29 15:34:23 BRST 2016
Comparison
wat vs grunt-contrib-watch

FAQs
EMFILE: Too many opened files.?
This is because of your system's max opened file limit. For OSX the default is very low (256). Temporarily increase your limit with ulimit -n 10480, the number being the new max limit.
In some versions of OSX the above solution doesn't work. In that case try launchctl limit maxfiles 10480 10480 and restart your terminal. See here.
