问题描述
我有一个散列,其中包含如下数据:
my %hash = (
'150' => {
'priority' => 'High','node' => 'Node1','delta' => '00:05:00'
},'170' => {
'delta' => '00:00:30','node' => 'Node2','priority' => 'Medium'
}
);
我正在使用foreach
循环并生成报告(.txt)文件对其进行迭代。
所以,我需要的格式如下:
EVENTID NODE DELTA PRIORITY
-------------------- -------------------- -------------------- --------------------
150 Node1 00:05:00 High
170 Node2 00:00:30 Medium
下面是我的脚本,用于格式化结果:
...
...
open(my $fh,'>',"report_file.txt") or die "Cannot open a file : $!";
printf $fh("%-20s %-20s %-20s %-20s\n",'EVENTID','NODE','DELTA','PRIORITY');
printf $fh("%-20s %-20s %-20s %-20s\n",'-'x20,'-'x20);
foreach my $key (sort keys %hash){
printf $fh("%-20s %-20s %-20s %-20s\n",$key,$hash{$key}{'node'},$hash{$key}{'delta'},$hash{$key}{'priority'});
}
close $fh;
print "END\n";
它给了我预期的报告,但想确认它是否正确?因为我在这里对空格(-20s)进行硬编码。还提到了将用作标题下划线的破折号(-),例如'-'x20
。
这是一个很好的方法,还是我们有其他替代方法可以完成此操作(任何预定义的Perl模块)?
解决方法
Perl为数据输出提供format
,它最适合您的目标
use strict;
use warnings;
my %events = (
'150' => {
'priority' => 'High','node' => 'Node1','delta' => '00:05:00'
},'170' => {
'delta' => '00:00:30','node' => 'Node2','priority' => 'Medium'
}
);
$^ = "STDOUT_TOP";
my($event,$priority,$node,$delta);
for $event (sort keys %events) {
($node,$delta,$priority) = @{$events{$event}}{qw/node delta priority/};
write;
}
format STDOUT_TOP =
EVENTID NODE DELTA PRIORITY
-------------------- -------------------- -------------------- --------------------
.
format STDOUT =
@<<<< @<<<<<<<<<<< @<<<<<<<<<<< @<<<<<<<<<<<
$event,$priority
.
输出
EVENTID NODE DELTA PRIORITY
-------------------- -------------------- -------------------- --------------------
150 Node1 00:05:00 High
170 Node2 00:00:30 Medium
附录:以下代码演示了如何使用格式将输出写入文件中
use strict;
use warnings;
my %events = (
'150' => {
'priority' => 'High','priority' => 'Medium'
}
);
my $fname = 'hash_events.txt';
open FILE,'>',$fname
or die "Couldn't open $fname: $!";
select(FILE);
$^ = "FILE_TOP";
my($event,$delta);
for $event (keys %events) {
($node,$priority) = @{$events{$event}}{qw/node delta priority/};
write;
}
close FILE;
format FILE_TOP =
EVENTID NODE DELTA PRIORITY
-------------------- -------------------- -------------------- --------------------
.
format FILE =
@<<<< @<<<<<<<<<<< @<<<<<<<<<<< @<<<<<<<<<<<
$event,$priority
.
,
还有Perl6::Form
,可让您在perl中使用Raku风格的格式,其中格式说明是函数的参数,而不是硬编码到程序中;基本上是sprintf
的类固醇。
#!/usr/bin/env perl
use warnings;
use strict;
use feature qw/say/;
use Perl6::Form;
my %hash = (
'150' => {
'priority' => 'High','priority' => 'Medium'
}
);
say 'EVENTID NODE DELTA PRIORITY';
say '-------------------- -------------------- -------------------- --------------------';
for my $key (sort { $a <=> $b } keys %hash) {
my $text = form
'{<<<<<<<<<<<<<<<<<<} {<<<<<<<<<<<<<<<<<<} {<<<<<<<<<<<<<<<<<<} {<<<<<<<<<<<<<<<<<<}',$key,@{$hash{$key}}{qw/node delta priority/};
print $text;
}
,
作为使用Perl代码进行格式化的替代方法,请考虑将您的任务分为2个子任务:
- 使用Perl以通用格式(例如制表符分隔的文件)写入输出,然后
- 使用不同程序包格式化制表符分隔的文件。
还请考虑是否需要在标题后加上破折号(-----
)。如果破折号是可选的,则可以将perl的tsv输出通过管道传输到* NIX column
实用程序中,如下所示:
perl_script_writing_tsv.pl | column -t -s$'\t'
在这里,-t -s$'\t'
选项将选项卡上的输入而不是默认的空格分隔开,并写出对齐的输出表,与您的输出表相似,但标题后没有破折号。
示例:
代码:
#!/usr/bin/env perl
use warnings;
use strict;
use feature qw( say );
# Renamed the hash for clarity: please rename according to your
# knowledge domain.
my %benchmarks_for_eventid = (
'150' => {
'priority' => 'High','priority' => 'Medium'
}
);
my $delim = "\t";
my @benchmarks_for_eventid_fields = qw( node delta priority );
say join $delim,map { uc } 'eventid',@benchmarks_for_eventid_fields;
# Using numeric 'sort',since eventids are likely integers,not
# strings:
foreach my $eventid ( sort { $a <=> $b } keys %benchmarks_for_eventid ) {
say join $delim,$eventid,map { $benchmarks_for_eventid{ $eventid }{ $_ } }
@benchmarks_for_eventid_fields;
}
script | column ...
的输出:
EVENTID NODE DELTA PRIORITY
150 Node1 00:05:00 High
170 Node2 00:00:30 Medium
使用column
打印以制表符分隔的文件,并使其对齐:
示例:
perl -le '
print join "\t",qw(col1 col2 col3);
print join "\t",q{r1 c1},q{r1 c2 loooooooong string},q{r1 c3};
print join "\t",q{r2 c1},q{r2 c2},q{r2 c3};
' | column -t -s$'\t'
打印:
col1 col2 col3
r1 c1 r1 c2 loooooooong string r1 c3
r2 c1 r2 c2 r2 c3