notify-when-up2

notify-when-up2 replaces notify-when-up.

The purpose

notify-when-up2 is for letting you know when something changes. It can:
- E-mail you
- Page (text) you
- Pop up a notification via libnotify
- Display an X11 popup or osascript
Examples of things you might notify on include
- A process dying - by pid or by name
- A process exiting with a particular status - true or false
- A program outputting a number less than or greater than a specific value
- Let you know when the output of a command changes
- A tcp port starts listening
- Pretty much anything you can write a shell command for that converts what you're interested in to one of the above

Usage:

Usage: /usr/local/bin/notify-when-up2 --true-command cmd
	-f|--false-command cmd                                        Loop until cmd returns shell-false
	-t|--true-command cmd                                         Loop until cmd returns shell-true
	-g|--greater-than fieldno cmd value                           Loop until fieldno of cmd output is > value
	-G|--greater-than-or-equal-to fieldno cmd value               Loop until fieldno of cmd output is >= value
	-l|--less-than fieldno cmd value                              Loop until fieldno of cmd output is < value
	-L|--less-than-or-equal-to fieldno cmd value                  Loop until fieldno of cmd output is <= value
	-e|--equal-to fieldno cmd value                               Loop until fieldno of cmd output is == value
	-p|--pid pid                                                  Loop until pid exists
	-c|--spawn-command cmd                                        Spawn cmd and loop until it exits
	-S|--pid-by-process-name process-name-regex                   Wait for pid (id'd by regex) to exit (flat view)
	-s|--pid-by-process-name-hierarchically process-name-regex    Wait for pid (id'd by regex) to exit (tree view)
	-n|--check-host-port host tcpport                             Wait for host:tcpport to listen
	-E|--email-address email-address
	-m|--max-seconds seconds
	-i|--check-interval n                                         Check every n seconds
	-r|--remote-host hostname                                     Check on hostname
	-b|--block
	-w|--no-blocking
	-P|--send-page
	   --delta command
	-d|--docker                                                   Prompt with a list of docker containers and use one
	-D|--docker-container dc                                      Use dc as docker container
	   --sudo                                                     sudo on the final hop. Does not try to authenticate
	-h|--help

Options are very order sensitive - EG, you need to specify
--remote-host before --pid, to make --pid operate on the correct
host.

Also, you can specify more than one checking option on the same command.
For example:
	/usr/local/bin/notify-when-up2 --pid 12345 --spawn-command "sleep 10" --pid 54321

Special (and optional) environment variables
	NWUEMAIL         The email address to send alerts to and from
	NWUPAGE          The email address to send pages to and from
	NWUMAILACCOUNT   The name of the account to which you wish to send e-mail

Please note that if sudo on the (remote) host requires a password, this program will appear to hang.

You can download it here. If you want the --remote-host feature, you need to install bashquote and deep-ssh.

About the differences between notify-when-up and notify-when-up2

The options are subtly different between the two, but the general idea is similar.
- Specifically, options in notify-when-up2 are order sensitive, while options in notify-when-up are not.
- This means if you give -m after -c, the -m won't impact the -c in notify-when-up2, but it would've in notify-when-up.
notify-when-up2 lets you give multiple checking options in the same run; notify-when-up did not. For example, with notify-when-up2 you can "notify-when-up2 -f false -t true", but in notify-when-up you would've gotten an error doing this.
notify-when-up2 is a complete rewrite. notify-when-up grew without planning; notify-when-up2 is much prettier inside.
notify-when-up2 adds the useful --remote-host option, that allows you to check things on remote hosts, without requiring e-mail or X11 to be feasible on remote hosts.
notify-when-up2 supports both GNU-style options like --true-command, and older unix style options like -t. notify-when-up only understands unix style options like -t.