ping: option requires an argument -- h
usage: ping [-AaDdfnoQqRrv] [-c count] [-G sweepmaxsize]
[-g sweepminsize] [-h sweepincrsize] [-i wait]
[-l preload] [-M mask | time] [-m ttl] [-p pattern]
[-S src_addr] [-s packetsize] [-t timeout][-W waittime]
[-z tos] host
ping [-AaDdfLnoQqRrv] [-c count] [-I iface] [-i wait]
[-l preload] [-M mask | time] [-m ttl] [-p pattern] [-S src_addr]
[-s packetsize] [-T ttl] [-t timeout] [-W waittime]
[-z tos] mcast-group
Apple specific options (to be specified before mcast-group or host like all options)
-b boundif # bind the socket to the interface
-k traffic_class # set traffic class socket option
-K net_service_type # set traffic class socket options
-apple-connect # call connect(2) in the socket
-apple-time # display current time
命令“ping -S 192.168.220.1 jingyan.baidu.com”就是指定ping的数据包从IP地址为192.168.220.1的网卡上发送出去。