entr

Run arbitrary commands when files change. More information: https://eradman.com/entrproject/.

• Rebuild with make if any file in any subdirectory changes:

ag -l | entr make

• Rebuild and test with make if any .c source files in the current directory change:

ls *.c | entr 'make && make test'

• Send a SIGTERM to any previously spawned ruby subprocesses before executing ruby main.rb:

ls *.rb | entr -r ruby main.rb

• Run a command with the changed file (/_) as an argument:

ls *.sql | entr psql -f /_

• clear the screen and run a query after the SQL script is updated:

echo my.sql | entr -cp psql -f /_

• Rebuild the project if source files change, limiting output to the first few lines:

find src/ | entr -s 'make | sed 10q'

• Launch and auto-reload a Node.js server:

ls *.js | entr -r node app.js