check_procs is an example for a plugin which doesn't deliver performance data:

    ./check_procs -a ndo2db -w 1: -c 0:
    PROCS OK: 2 processes with args 'ndo2db'

This can be changed with the following wrapper script

check_procs.sh

    #!/bin/bash
    LINE=`/usr/local/nagios/libexec/check_procs $*`
    RC=$?
    COUNT=`echo $LINE | awk '{print $3}'`
    echo $LINE \| procs=$COUNT
    exit $RC

Now you'll get the number together with the required label

    ./check_procs.sh -a ndo2db -w 1: -c 0:
    PROCS OK: 2 processes with args 'ndo2db'| procs=2