perl - Perl 使用 ping 抑制反引号输出

Question

抑制 Perl 代码的系统输出。

这段代码在功能上运行良好，直到我遇到无法解析的主机名并想要抑制无法解析的域的输出。

如果 lists.hosts 文件中有一个域无法解析，屏幕输出将包含：“ping: cannot resolve XXX.com: Unknown host”

my $ip;

open(HOSTLIST, "lists.hosts");    # Load domains
@hosts = <HOSTLIST>;
chomp($host);

foreach $host (@hosts) {

  $results = `ping -c 1 $host`;

  $record++;

  my $pos = index($results, $find);

  if (($results =~ /ttl=/) || ($results =~ /data bytes/)) {
    #$count++;
    chomp($host);
    if (($results =~ /(?<=bytes from)(.*)(?=:)/) != 0) {
      ($ip) = ($results =~ /(?<=bytes from)(.*)(?=:)/);
    }
    elsif (($results =~ /(?<=\()(.*)(?=\))/) != 0) {
      ($ip) = ($results =~ /(?<=\()(.*)(?=\))/);
    }

    print "Record: $record Host: $host IP:$ip Status: Passed";
    print "\n";

    #print ("*** Record# $record: Ping Test Succeeded for Server: $host ***\n");
    #print ("$results\n");
  }
  else {
    $count++;
    chomp($host);

    #print ("*** Record# $record: Ping Test Failed for Server: $host ***\n");
    print "Record: $record Host: $host Status: Failed\n";

    #print ("$results\n");
  }
}

close(HOSTLIST);

exit($errorcode);

Answer 1

您调用ping需要捕获标准错误：

ping -c 1 $host 2>&1

此外，您没有检查您的退货，open您应该始终这样做。最后，您应该在顶部使用use warnings;和。use strict;