在Perl中分解qx/ return

Question

​

我有一台Ubuntu 16.04.1服务器，我在上面胡乱摆弄。目前，我正在使用它来监控我的网速和连接。

我已经编写了一个脚本，并使用Perl和crontab将其自动化，但现在我想清理一下我的日志文件。

以下是在执行Perl脚本时写入日志文件的内容：

Time: 12:40:01
Retrieving speedtest.net configuration...
Testing from TWC (now Spectrum) (123.45.67.890)...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by Fibrant (Salisbury, NC) [60.95 km]: 51.184 ms
Testing download     speed................................................................................
Download: 37.76 Mbit/s
Testing upload speed....................................................................................................
Upload: 11.56 Mbit/s

相反，我希望输出为：

Download: 37.76 Mbit/s
Upload: 11.56 Mbit/s

我当前的Perl脚本如下所示：

    use strict;
    use warnings;

    my ( $sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst ) = localtime( time );
    my $nice_timestamp = sprintf( "%04d%02d%02d",   $year + 1900, $mon + 1, $mday );
    my $timer          = sprintf( "%02d:%02d:%02d", $hour,        $min,     $sec );
    my $filename = "/home/user/DailyLogs/InternetLog$nice_timestamp";

    open( my $fh, '>>', $filename ) or die "Could not open file '$filename' $!";

    my $output = qx"/home/user/.local/bin/speedtest-cli";

    print $fh "Time: ";
    print $fh $timer;
    print $fh "\n";
    print $fh $output;
    print $fh "\n\n";

    close $fh;

任何帮助都将不胜感激。谢谢!

Answer 1

您可以使用grep过滤qx输出

my @output = grep {/^(Up|Down)load:/} qx"/home/user/.local/bin/speedtest-cli";
print $fh $_ for @output;

顺便说一句，您可以使用POSIX简化$timer代码

use POSIX qw(strftime);
my @localtime = localtime;
my $nice_timestamp = strftime('%Y%m%d',   @localtime);
my $timer          = strftime('%H:%M:%S', @localtime);

Answer 2

如果您将结果赋值给一个数组，Backticks ( qx运算符)将把输出拆分为几行。您可以使用grep选择您想要查看的行

我还将使用Time::Piece模块来生成时间和日期字符串

代码将如下所示

use strict;
use warnings 'all';

use Time::Piece;

my $now = localtime;
$now->date_separator('');
my $nice_timestamp = $now->ymd; # Generates YYYYMMDD

my $filename = "/home/user/DailyLogs/InternetLog$nice_timestamp";

open my $fh, '>>', $filename or die qq{Unable to open file "$filename" for appending: $!};

my @output = qx</home/user/.local/bin/speedtest-cli>;

my $timer = $now->hms; # Generates HH:MM:SS

print $fh "Time: $timer\n";
print $fh for grep /^(?:Down|Up)load/, @output;
print $fh "\n\n";

close $fh;