Perl if-then-else 逻辑以及如果正则表达式不匹配如何处理无数据

Question

到目前为止，我有一些工作代码进入服务器列表并执行一些正则表达式以从日志文件中获取数据。我想要做的是，如果没有可以从特定服务器上的正则表达式捕获的数据，则显示“没有任何可报告此服务器”的状态。

现在，它会遍历每个服务器，如果数据与正则表达式匹配，它将打印出来。 我添加了一个 else 语句来打印上面的语句来处理这个问题，但现在它为每个不匹配的实例打印它。

这是输出的副本，因为它现在可以工作之前我添加了更改：

========================================================================
REPORTING SUMMARY for BACKUP SERVER : hostname1
========================================================================
REPORTING SUMMARY for BACKUP SERVER : hostname2
Mon Jul 05 00:30:02 2010: hostname2:backup:INFO: backup-date=20100705003002
Mon Jul 05 00:30:02 2010: hostname2:backup:INFO: host=hostname2
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-size=49.75 GB
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-time=00:25:23
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-status=Backup succeeded
========================================================================

这是现在输出的副本，之后我添加了“没有什么可报告的” DATE":（在 while 循环内）。基本上，每次不匹配时它都会打印出这个语句。我真的只是想让它给我一个声明。

========================================================================
REPORTING SUMMARY for BACKUP SERVER : hostname1
NOTHING TO REPORT FOR THIS DATE... 
NOTHING TO REPORT FOR THIS DATE... 
NOTHING TO REPORT FOR THIS DATE... 
...
...
========================================================================
NOTHING TO REPORT FOR THIS DATE... 
Mon Jul 05 00:30:02 2010: hostname2:backup:INFO: backup-date=20100705003002
Mon Jul 05 00:30:02 2010: hostname2:backup:INFO: host=hostname2 
NOTHING TO REPORT FOR THIS DATE... 
NOTHING TO REPORT FOR THIS DATE...
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-size=49.75 GB
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-time=00:25:23
Mon Jul 05 00:55:25 2010: hostname2:backup:INFO: backup-status=Backup succeeded

这是代码：

# Usage: ./test.pl Ju1 05 2010 <logfilepath> hostname1 hostname2 hostname3
use strict;
use warnings;
my($mon,$day,$year,$file) = @ARGV;
splice(@ARGV, 0, 4, ());            
foreach my $server ( @ARGV ) {      
    print "========================================================================\n";
    print "REPORTING SUMMARY for BACKUP SERVER : $server\n";
    open(my $fh,"ssh $server cat $file |") or die "can't open log $server:$file: $!\n";
    while (my $line = <$fh>) {
        if ($line =~ m/.* $mon $day \d{2}:\d{2}:\d{2} $year:.*(host=|ERROR:|backup-date=|backup-size=|backup-time=|backup-status)/) {
            print $line;
            # adding else statement here
            } else {
            print "NOTHING TO REPORT FOR THIS DATE... \n";
        }
    }
    close($fh);
}

Answer 1

1. 将布尔值设置为 false。
2. 在 while 循环内，如果正则表达式匹配，则将布尔值设置为 true。
3. 在 while 循环之外，如果布尔值仍然为 false，则打印 NOTHING TO REPORT。

Answer 2

这现在有效：

use strict;
use warnings;
my($mon,$day,$year,$file) = @ARGV;
my $has_data = 0;
splice(@ARGV, 0, 4, ());            
foreach my $server ( @ARGV ) {     
    print "========================================================================\n";
    print "REPORTING SUMMARY for BACKUP SERVER : $server\n";
    open(my $fh,"ssh $server cat $file |") or die "can't open log $server:$file: $!\n";
    while (my $line = <$fh>) {
        if ($line =~ m/.* $mon $day \d{2}:\d{2}:\d{2} $year:.*(host=|ERROR:|backup-date=|backup-size=|backup-time=|backup-status)/) {
            print $line;
            $has_data=1; #set to true
            #print "Boolean is set to $has_data \n";
        }
    } #end while loop
        if ($has_data==0) {
           print "Boolean is set to $has_data \n";
           print "NOTHING TO REPORT FOR THIS DATE... \n";
        }
       $has_data=0;
       print "Boolean is reset to $has_data \n";
    close($fh);
}

Answer 3

我不认为，我做对了。我按照建议（@mcandre）尝试并放置在 while 循环之外，但仍然得到相同的行为。我应该把这张支票放在哪里？

use strict;
use warnings;
my($mon,$day,$year,$file) = @ARGV;
my $boolean = 0;
splice(@ARGV, 0, 4, ());            
foreach my $server ( @ARGV ) {      
    print "========================================================================\n";
    print "REPORTING SUMMARY for BACKUP SERVER : $server\n"; 
    open(my $fh,"ssh $server cat $file |") or die "can't open log $server:$file: $!\n";
    while (my $line = <$fh>) {
        if ($line =~ m/.* $mon $day \d{2}:\d{2}:\d{2} $year:.*(host=|ERROR:|backup-date=|backup-size=|backup-time=|backup-status)/) {
            print $line;
            $boolean=1; #set to true
            #print "Boolean is set to $boolean \n";
        }
    } #end while loop
        if ($boolean=0) {
           print "Boolean is set to $boolean \n";
           print "NOTHING TO REPORT FOR THIS DATE... \n";
        }
    close($fh);
}