#!/usr/bin/awk -f
#
# USAGE:
# make this script executable with `chmod +x dhcpparse.awk` and then
#
#   cat dhcpd.conf|./dhcpparse.awk|sort
 
# set the RECORD SEPARATOR, RS, to "}" ... records span multiple lines
BEGIN {RS="}"}
 
# TODO: figure out how to skip comment lines without having to use sed first
 
length($0) > 5 { total++
 
  for(i=1;i<=NF;i++) {
 
    counter[total] = total
 
    # if this field matches the word "host"
    if($i ~ /^host$/) {
      type[total] = "host"
      hostname[total]=$(i+1)
      # Remove the trailing { that might be there
      gsub(/{/, "", hostname[total])
    }
 
    # if this field matches the word "hardware"
    else if($i ~ /^hardware$/) {
 
      # get rid of the trailing semi-colon
      split($(i+2),arr,";")
 
      mac[total]=arr[1]
    }
 
    # if this field matches the word "fixed-address"
    else if($i ~ /^fixed-address$/) {
 
      # get rid of the trailing semi-colon
      split($(i+1),arr,";")
 
      ip[total]=arr[1]
    }
 
    # if this field matches the word "subnet-mask"
    else if($i ~ /^subnet-mask$/) {
 
      # get rid of the trailing semi-colon
      split($(i+1),arr,";")
 
      subnet[total]=arr[1]
    }
 
  # if this field matches the word "routers"
    else if($i ~ /^routers$/) {
 
      # get rid of the trailing semi-colon
      split($(i+1),arr,";")
 
      routers[total]=arr[1]
    }
 
# if this field matches the word "domain-name-servers"
    else if($i ~ /^domain-name-servers$/) {
 
      # get rid of the trailing semi-colon
      split($(i+1),arr,";")
 
      domains[total]=arr[1]
    }
 
# if this field matches the word "boot-file-name"
    else if($i ~ /^bootfile-name$/) {
 
      # get rid of the trailing semi-colon
      split($(i+1),arr,";")
 
      boot[total]=arr[1]
    }
 
 
 
  }
 
 
 
}
 
# for every entry we captured, display its appropriate info
END { for(entry in counter) {
         if(type[entry] == "host") {
             printf("ip=%s mac=%s subnet=%s hostname=%s routers=%s domains=%s boot=%s  \n",\
                 ip[entry],mac[entry],subnet[entry],hostname[entry],routers[entry],domains[entry],boot[entry])
         }
    }
}