Shell Programming and Scripting

Hi,
I need a help that i want to get the IP which is located at the first line of lease block, using mac id i have to get that ip....In between IP and MAC, the number of lines may vary.....i tried using Grep before 5 line and using awk i took the IP...But the scenario am facing is that number of lines in between IP and mac may change.

Any help is appreciated....


lease 172.19.134.240 {
starts 4 2010/03/04 11:00:26;
ends 4 2010/03/04 20:00:26;
tstp 4 2010/03/04 20:00:26;
binding state active;
next binding state free;
hardware ethernet 00:23:5e:05:1f:02;
uid "\000cisco-0023.5e05.1f02-Fa0.14";
option agent.circuit-id "eth0";
client-hostname "WAP";
}


Thanks in Advance

Code:

# mac="00:23:5e:05:1f:02"
# awk -v mac=$mac '/lease/{ip=$2}$0 ~ mac{print ip}' logfile

Code:

nawk -f  sm.awk -v mac='00:23:5e:05:1f:02' sm.txt

sm.awk:

Code:

BEGIN {
  FS=" |;"
}
/^lease/ {ip=$2;next}
/^hardware ethernet/ && $3==mac {print ip}

Thank you for your ideas!!!!