[ Perl ] HASH 读写

https://www.cnblogs.com/yeungchie/

便于数据结构的存储和还原
这里的方法是将 HASH 转为 字符串 写入文件的，再读取文件中字符串内容转为 HASH
使用 JSON 作为数据交换格式 ( JavaScript Object Notation )

使用 JSON 模块

use JSON;

HASH 转 JSON

• hashToJson.pl

# 省略一堆次要的模块声明

use JSON;

my %hash_data = (
    server   => "eda",
    release  => "6.10",
    memTotal => "15G",
    memRatio => "0.144396",
    cores    => "6",
    cpuRatio => "0.0145719489981785",
    time     => "1624202821",
    load     => "0.29/0.07/0.02",
);
say Dumper \%hash_data;

my $json = new JSON;                                # 创建 JSON 对象
my $json_data = $json->pretty->encode(\%hash_data); # 编码成 JSON 格式

say Dumper \$json_data;

# JSON 写入
my $file = IO::File->new('>hashToJson.txt');
printf $file $json_data;
$file->close;

hash_data
$VAR1 = {
'memRatio' => '0.144396',
'memTotal' => '15G',
'cores' => '6',
'cpuRatio' => '0.0145719489981785',
'time' => '1624202821',
'server' => 'eda',
'release' => '6.10',
'load' => '0.29/0.07/0.02'
};

json_data
$VAR1 = '{
"memRatio" : "0.144396",
"memTotal" : "15G",
"cores" : "6",
"cpuRatio" : "0.0145719489981785",
"time" : "1624202821",
"server" : "eda",
"release" : "6.10",
"load" : "0.29/0.07/0.02"
}
';

JSON 转 HASH

jsonToHash.pl

# 省略一堆次要的模块声明

use JSON;

# JSON 读取
my $file = new IO::File '<hashToJson.txt';
my @file_data = <$file>;
$file->close;
my $json_data = join '',@file_data;
say Dumper \$json_data;

# 解码
my $hash_data = decode_json $json_data;
say Dumper $hash_data;

# Tips : 解引用 %{$hash_data}

json_data
$VAR1 = '{
"memRatio" : "0.144396",
"memTotal" : "15G",
"cores" : "6",
"cpuRatio" : "0.0145719489981785",
"time" : "1624202821",
"server" : "eda",
"release" : "6.10",
"load" : "0.29/0.07/0.02"
}
';

hash_data
$VAR1 = {
'time' => '1624202821',
'release' => '6.10',
'server' => 'eda',
'memRatio' => '0.144396',
'memTotal' => '15G',
'load' => '0.29/0.07/0.02',
'cpuRatio' => '0.0145719489981785',
'cores' => '6'
};