使用Perl解析JSON

时间:2016-09-21 18:53:56

标签: perl perl-module

我编写了一个测试脚本来执行某些功能。脚本按预期工作。目前,运行脚本所需的参数是使用Getopt::Long从命令行传递的。我想将命令行参数移动到json文件。端点ip仍将作为命令行arg传递。 我希望端点ip充当密钥。例如,如果端点是1.1.1.1,我想获得下面提到的json配置文件中端点id 1.1.1.1下列出的client_ip,client_interface_ip,originip,....端口。我该怎么做?

当前版本的脚本:

 use Getopt::Long;

     my ($self) = @_;

        GetOptions (
            "endpoint|e=s"           => \$self->{'endpoint'},
            "aggregator|a=s"         => \$self->{'aggregator'},
            "port|pt=s"              => \$self->{'port'},
            "client|c=s"             => \$self->{'client'},
            "client_interface|ci=s"  => \$self->{'client_interface'},
            "origin|o=s"             => \$self->{'origin'},
            "origin_interface|oi=s"  => \$self->{'origin_interface'},
            "interfacename|ot=s"     => \$self->{'i1'},
            "interfacename2|it=s"    => \$self->{'i2'},
             ) || $self->abort( "Invalid command line options.
                   Valid options are endpoint,aggregator,port,client,client_interface,
                     origin,origin_interface,outertunnel,innertunnel,");

       #Terminate the script execution if the reqd args are not passed
       my @required_args = qw(endpoint aggregator port client client_interface            origin origin_interface 
                              );

       for my $command_line_arguments (@required_args) {
         unless ($self->{$command_line_arguments}) {
          $self->abort('missing required argument ' . $command_line_arguments);
         }
       }

  $self->{'tObj'} =  QA::crypto::tunnels->new
      ('host'=> $self->{'endpoint'})
         or $self->abort('[Could not create a QA::Crypto::tunnels object.]');

参数的json文件:

{
        "Endpoints": [{

                "endpoint": "1.1.1.1",
                "client_ip": "3.4.5.6",
                "client_interface_ip": "10.11.12.14",
                "origin": "a.a.a.a",
                "origin_interface": "15.16.17.18",
                "interfacename": "name",
                "interfacename2": "name1",
                "sl": 19,
                "port": 362
        }, {

                "endpoint": "2.2.2.2",
                "client_ip": "19.20.21.22",
                "client_interface_ip": "23.24.25.26",
                "origin": "1.2.3.4",
                "origin_interface": "5.6.7.8",
                "interfacename": "interface name",
                "interfacename2": "interfacename_2",
                "sl": 19,
                "port": 366
        }]
}




#!/usr/bin/perl

use strict;
use warnings;
use JSON;

my $json;
{
   open my $fh, "<", "cfg.txt"
      or die("Can't open file \"cfg.json\": $!\n");
   local $/;
   $json = <$fh>;
}

my $data = decode_json($json);
$json = JSON->new->utf8->pretty->encode($data);

1 个答案:

答案 0 :(得分:3)

第一个问题是关于JSON文件的合适设计。哈希可以在这里很好地服务,而似乎根本不需要arrayref。端点值可以是键,其值是具有密钥相关信息的hashref。如果愿意,也可以将端点值保留在hashref中。

JSON中的密钥"Endpoints"似乎没有做多少。但是如果你确实需要它,也许因为会有其他类型的键,那么你可以为它的值另一个hashref,它将包含带端点值作为键的hashref。

例如

{ 
   "Endpoints": { 
        "1.1.1.1": { "client_ip": "3.4.5.6",     ... },
        "2.2.2.2": { "client_ip": "19.20.21.22", ... },
        ...
   }, 
   "OtherKeys": { ... }, ...
}

最后的值不应以逗号结尾。请参阅JSON format

当你将它带入Perl时,你将拥有嵌套的hashrefs,比如

$data = { 
    Endpoints => { 
         1.1.1.1 => { client_ip => '3.4.5.6',     ... }, 
         2.2.2.2 => { client_ip => '19.20.21.22', ... },
    }, 
    OtherKeys => { ... }, 
};

然后将值简单地检索为

my $client_ip = $data->{Endpoints}{'1.1.1.1'}{client_ip};

例如,检索所有端点并为其列出client_ip

my @endpoints = keys %{$data->{Endpoints}};
foreach my $ip (@endpoints) {
    say $data->{Endpoints}{$ip}{client_ip};
}

请参阅Using References in perlrefthis post完全是关于它的。另请参阅perlreftutperldsc

我们可以使用Data::Dumper

检查(参见)整个数据结构
use Data::Dumper;
my $data = decode_json($json);
print Dumper($data);

还有许多其他包用于处理嵌套数据结构。

请注意,JSON包附带encode_json及相关方法,因此您可以通过编程方式创建该文件。这可能有助于使其格式正确并在将来进行维护。