awk获取ip地址

linux-dduk:~ # time ifconfig eth0|grep 'inet addr'|awk -F ":" '{print $2}'|awk '{print $1}' 
192.168.12.152

real    0m0.010s
user    0m0.004s

sys     0m0.004s

linux-dduk:~ # time ifconfig eth0|grep 'inet addr'|awk -F '[ :]' '{print $13}'
192.168.12.152

real    0m0.005s
user    0m0.004s

sys     0m0.000s

linux-dduk:~ # time ifconfig eth0 |awk -F '[ :]+' 'NR==2 {print $4}'
192.168.12.152

real    0m0.003s
user    0m0.004s

sys     0m0.000s

linux-dduk:~ # time ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:0C:29:4A:73:95  
          inet addr:192.168.12.152  Bcast:192.168.12.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe4a:7395/64 Scope:Link
          UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6099 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1588 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:643137 (628.0 Kb)  TX bytes:1074048 (1.0 Mb)
          Base address:0x2000 Memory:d8920000-d8940000 

real    0m0.002s
user    0m0.000s
sys     0m0.000s