Waits for write, rename and delete events on files and file creation and deletion events in directories and returns. Please note, that simply touching a file will not trigger a return.
Supports waiting on multiple files and directories. When waiting on a directory, adding a file, or deleting a file will trigger a return. Everything else (like touching or writing) will not trigger a return.
Mac OS X
- Xcode (Command Line Tools suffice)
Waiting on directories does not work on Linux at the moment.
To build this just type:
If you want to check that everything is working correctly on your computer use:
This requires perl, with modules
Call it like this:
kqwait [-d] [-v] [-h] <file|dir>[ <file|dir>]+
d- enable debugging
v- print version
h- print help
The tool prints the file or directory that caused the tool to wake up,
0, if the expected event occured,
When waiting on a directory, a
+ character is prepended if a file was
- if a file was deleted.
Use it in a shell script like this:
while ./kqwait text.txt; do # do some stuff on write done
Or watch directories like this:
$ while ./kqwait somedir someotherdir; do true; done + somedir/a_file_was_added.txt - someotherdir/a_file_was_deleted.txt
When watching directories, write events concerning existing files currently won't trigger a return. Only creation and deletion will do that. If you would like to track all events at the same time you can use shell mechanisms to do that:
while ./kqwait dir1/ dir1/*; do # something done
If you want to use the file that caused the return, you can assign the output to a variable:
while file=`./kqwait dir1/`; do echo "Event on $file" done
See a more advanced script, that does some simple dispatch based on file
There is (at least) one race condition in this code, when waiting for changes on directories. If several events happen on a directory in quick succession, this tool might catch an intermediate snapshot of that chain of events.
Sven Schober email@example.com
Copyright (c) 2013, Sven Schober All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.