Bash script Nagios plugin used to analyse vmstat(8) output.

Inspired by check_apache2.

$ ./check_vmstat --help
Version 0.2, 2012, Jon Bevan (https://github.com/jdbevan)

Description:
check_vmstat is a Nagios plugin to monitor the output of 
vmstat(8) on a server. It returns a mean value based on a number
of updates for all the values provide by vmstat by default unless
specified otherwise using the arguments below.

Example calls:
./check_vmstat -P -C -Y --delay 1 --count 20
./check_vmstat --output memory,swap,io -d 3

Options:
  -P|--procs)
    Display the procs figures.
  -M|--memory)
    Display the memory figures.
  -W|--swap)
    Display the swap figures.
  -I|--io)
    Display the I/O figures.
  -Y|--system)
    Display the system figures.
  -C|--cpu)
    Display the cpu figures.

  -d|--delay)
    The delay in seconds between vmstat updates in seconds. If not 
    provided then the figures returned are the averages since system
    boot.
  -c|--count)
    The number of vmstat updates. Ignored if delay is not specified.
    Default value is 5.
  -o|--output)
    Comma separated string specifying the data output from: procs,
    memory, swap, io, system, cpu, all.
    Added to options -P -M -W -I -Y and -C. Default: all.

TODO: Allow specification of critical/warning limits as optional arguments to follow output specifiers