#!/bin/bash
#
# proc-count.sh [-f filter]... [-c] email
#  - Simple process counting tool
#
# Changelog:
#  * 2014-05-22 - Nathan Isburgh <nathan@edgecloud.com>
#               - Initial version of script
#               - Implemented basic counts, filters, and outputs
#

# Debug flag - 1 for verbose debugging
DEBUG=1

#
# NO EDITS BELOW THIS LINE
#

#
# succeed()
#  - gracefully exit from program successfully
#
succeed() {
  cleanup
  exit 0
}

#
# fail( code, msg )
#  - gracefully exit from program in failure state
#
fail() {
  cleanup
  if [ -n "$2" ]
  then
    echo "$2" > /dev/stderr
  fi
  exit ${1:-1}
}

#
# cleanup()
#  - clean up log/lock files, etc
#
cleanup() {
  return
}

#
# debug( msg )
#  - Prints standard debug message to stderr
#  - Only print if debugging is enabled
#
debug() {
  if [ "$DEBUG" -ne 1 ]
  then
    return
  fi
  echo $(date +%T) " $@" > /dev/stderr
}

#
# usage()
#  - Print a basic usage statement for user to understand program use
#
usage() {
  cat << eof
Usage:
    $0 [-f filter]... [-c] email
   Sends report of process counts to email
 -f filter   Filter process list by 'filter'
 -c          Produce a CSV report, instead of TSV
 email       Email recipient for the generated reports
eof
}

#
# proc-count()
#  - Heavy lifter for producing process count report and emailing it
#    to $EMAIL
#
proc-count() {
  # Two scenarios:
  #  1) No filters given, produce full report
  #  2) Filters given, produce filtered report
  if [ ${#FILTERS[*]} -eq 0 ]
  then
    ps -Ao comm= | sort | uniq -c | awk -v OFS=$SEP '{print $2,$1}'
  fi
  for filter in ${FILTERS[*]}
  do
    ps -Ao comm= | fgrep $filter | sort | uniq -c | awk -v OFS=$SEP '{print $2,$1}'
  done 
}

# Main code body
# ...

SEP="\t"
FILTERS=()

while getopts ":f:c" opt; do
  case $opt in
    f)
      debug "filter requested: '$OPTARG'"
      FILTERS+=("$OPTARG")
      ;;
    c)
      debug "CSV output requested"
      SEP=","
      ;;
    \?)
      usage
      fail 1 "Invalid option: -$OPTARG"
      ;;
    :)
      usage
      fail 2 "Option -$OPTARG requires an argument."
      ;;
  esac
done

eval EMAIL=\${$OPTIND}

# Make sure the user supplied an email address
if [ -z "$EMAIL" ]
then
  usage
  fail 3 "Please supply an email address for the reports"
fi

proc-count | mailx -s "Process count" $EMAIL

succeed