mxcl/homebrew — pull request #10739 by isao (2012-03-07 07:23:54+00:00)
Title: wait_on - watch files or dirs using fsevent/kqueue (no polling) i.e. from shell scripts

The wait_on command waits for something to happen to the files or direc-
tories given as arguments and then exits. It is anticipated that the
wait_on command will be called from a shell script, allowing, for exam-
ple, a script to sleep until files have been added to a directory or data
is appended to a file. ** No polling is required **