Perl getprotoent 函数

描述

getprotoent 此函数返回有效协议列表中的下一个条目：（$name，$aliases，$protocol_number）。

句法

以下是此函数的简单语法-


getprotoent

返回值

此函数对错误返回undef，否则返回标量上下文中的协议编号，并在列表上下文中返回错误协议记录上的空列表（名称，别名，协议编号）。

示例

以下是显示其基本用法的示例代码-

 
while(($name, $aliases, $protocol_number) = getprotoent()) {
   print "Name = $name\n";
   print "Aliases = $aliases\n";
   print "Protocol Number = $protocol_number\n";
}

尝试一下

执行结果：


Name = ip
Aliases = IP
Protocol Number = 0
Name = hopopt
Aliases = HOPOPT
Protocol Number = 0
Name = icmp
Aliases = ICMP
Protocol Number = 1
Name = igmp
Aliases = IGMP
Protocol Number = 2
Name = ggp
Aliases = GGP
Protocol Number = 3
Name = ipencap
Aliases = IP-ENCAP
Protocol Number = 4
Name = st
Aliases = ST
Protocol Number = 5
Name = tcp
Aliases = TCP
Protocol Number = 6
Name = egp
Aliases = EGP
Protocol Number = 8
Name = igp
Aliases = IGP
Protocol Number = 9
Name = pup
Aliases = PUP
Protocol Number = 12
Name = udp
Aliases = UDP
Protocol Number = 17
Name = hmp
Aliases = HMP
Protocol Number = 20
Name = xns-idp
Aliases = XNS-IDP
Protocol Number = 22
Name = rdp
Aliases = RDP
Protocol Number = 27
Name = iso-tp4
Aliases = ISO-TP4
Protocol Number = 29
Name = dccp
Aliases = DCCP
Protocol Number = 33
Name = xtp
Aliases = XTP
Protocol Number = 36
Name = ddp
Aliases = DDP
Protocol Number = 37
Name = idpr-cmtp
Aliases = IDPR-CMTP
Protocol Number = 38
Name = ipv6
Aliases = IPv6
Protocol Number = 41
Name = ipv6-route
Aliases = IPv6-Route
Protocol Number = 43
Name = ipv6-frag
Aliases = IPv6-Frag
Protocol Number = 44
Name = idrp
Aliases = IDRP
Protocol Number = 45
Name = rsvp
Aliases = RSVP
Protocol Number = 46
Name = gre
Aliases = GRE
Protocol Number = 47
Name = esp
Aliases = IPSEC-ESP
Protocol Number = 50
Name = ah
Aliases = IPSEC-AH
Protocol Number = 51
Name = skip
Aliases = SKIP
Protocol Number = 57
Name = ipv6-icmp
Aliases = IPv6-ICMP
Protocol Number = 58
Name = ipv6-nonxt
Aliases = IPv6-NoNxt
Protocol Number = 59
Name = ipv6-opts
Aliases = IPv6-Opts
Protocol Number = 60
Name = rspf
Aliases = RSPF CPHB
Protocol Number = 73
Name = vmtp
Aliases = VMTP
Protocol Number = 81
Name = eigrp
Aliases = EIGRP
Protocol Number = 88
Name = ospf
Aliases = OSPFIGP
Protocol Number = 89
Name = ax.25
Aliases = AX.25
Protocol Number = 93
Name = ipip
Aliases = IPIP
Protocol Number = 94
Name = etherip
Aliases = ETHERIP
Protocol Number = 97
Name = encap
Aliases = ENCAP
Protocol Number = 98
Name = pim
Aliases = PIM
Protocol Number = 103
Name = ipcomp
Aliases = IPCOMP
Protocol Number = 108
Name = vrrp
Aliases = VRRP
Protocol Number = 112
Name = l2tp
Aliases = L2TP
Protocol Number = 115
Name = isis
Aliases = ISIS
Protocol Number = 124
Name = sctp
Aliases = SCTP
Protocol Number = 132
Name = fc
Aliases = FC
Protocol Number = 133
Name = mobility-header
Aliases = Mobility-Header
Protocol Number = 135
Name = udplite
Aliases = UDPLite
Protocol Number = 136
Name = mpls-in-ip
Aliases = MPLS-in-IP
Protocol Number = 137
Name = manet
Aliases = 
Protocol Number = 138
Name = hip
Aliases = HIP
Protocol Number = 139
Name = shim6
Aliases = Shim6
Protocol Number = 140
Name = wesp
Aliases = WESP
Protocol Number = 141
Name = rohc
Aliases = ROHC
Protocol Number = 142