正则表达式之间的选择性打印

Question

我需要从 REGEXP 捕获文本文件的 CSV 部分，直到第二个空行。如下所示：

garbage garbage
garbage garbage
garbage garbage

REGEXP

data,data,data
data,data,data

garbage garbage
garbage garbage
garbage garbage

任何如何在 sed 或 perl 中执行此操作的想法将不胜感激。

Answer 1

perl -00 -ne 'print, print(scalar <>), exit if /REGEXP/' file.txt

Answer 2

perl -ne '$on=1 if /REGEXP/; if ($on) { print; $blank++ if /^\s*$/; last if $blank == 2 }' file.csv

会显示：

    REGEXP

data,data,data
data,data,data

如果不想显示REGEXP：

perl -ne '$on=1 and next if /REGEXP/; if ($on) { print; $blank++ if /^\s*$/; last if $blank == 2 }' file.csv

Answer 3

像这样的事情：

#!/usr/bin/perl

use warnings; use strict;

while (<DATA>) {
    /^REGEXP/ and last;
}

my $csv_line;

while ($csv_line = <DATA>) {
    $csv_line =~ /,/ and last;
}

while (defined($csv_line) and $csv_line =~ /\S/) {
    process_csv($csv_line);
    $csv_line = <DATA>;
}

sub process_csv {
    my ($line) = @_;
    print $line;
}


__DATA__
garbage garbage
garbage garbage
garbage garbage

REGEXP

data,data,data
data,data,data

garbage garbage
garbage garbage
garbage garbage

Answer 4

使用记录输入分隔符捕获以双换行符结尾的块。这仅打印数据部分。如果要打印 REGEXP 部分，请取消注释 say;

$/ = "";
while (<>) {
    next unless /^REGEXP/;
    #say;  # Uncomment to print header
    chomp($_ = <>);
    say;
}