Perl getprotoent用法及代碼示例

描述

此函數返回有效協議列表中的下一個條目：($name, $aliases, $protocol_number)

用法

以下是此函數的簡單語法 -

getprotoent

返回值

此函數在錯誤時返回 undef，否則返回標量上下文中的協議編號和列表上下文中錯誤協議記錄(名稱、別名、協議編號)的空列表。

示例

以下是顯示其基本用法的示例代碼 -

#!/usr/bin/perl

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

執行上述代碼時，會產生以下結果 -

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 = udplite
Aliases = UDPLite
Protocol Number = 136
Name = mpls-in-ip
Aliases = MPLS-in-IP
Protocol Number = 137
Name = manet
Aliases = manet
Protocol Number = 138
Name = hip
Aliases = HIP
Protocol Number = 139
Name = shim6
Aliases = Shim6
Protocol Number = 140