Question

我有一个现有的Perl脚本，它会像这样吐出文本：

set a = 4
set b = 5
set c = 0
set d = 3

现在我想修改此脚本以更新文本文件的内容。该文件看起来像这样：

...

// BEGIN

set a = 1
set b = 4
set c = 5

// END

...

如何使用现有Perl脚本生成的文本替换// BEGIN和// END之间的行？

Answer 1

-用作第二个＆＃34;文件＆＃34;阅读STDIN，

perl existing.pl | perl -pe'
  BEGIN{ local @ARGV=pop; @c =<> }
  $r = /BEGIN/ .. /END/;
  if ($r >1 and $r !~ /E0/) { $_ = ""; print @c if $r ==2 }
' file -

输出

...
...

// BEGIN
set a = 4
set b = 5
set c = 0
set d = 3
// END

..
..

Answer 2

只需使用$INPLACE_EDIT或perlfaq5 - How do I change, delete, or insert a line in a file, or append to the beginning of a file?

中演示的任何其他方法即可

use strict;
use warnings;
use autodie;

my $file = 'file.txt';

# Your script generated data:
my $newdata = do { local $/; <DATA> };

# Insert new content
local @ARGV = $file;
local $^I   = '.bak';
while (<>) {
    if ( my $range = m{// BEGIN} .. m{// END} ) {
        print if $range == 1;
        print "$newdata$_" if $range =~ /E/;
    } else {
        print;
    }
}
unlink "$file$^I";    # Optionally delete backup

__DATA__
set a = 4
set b = 5
set c = 0
set d = 3

如何在固定关键字之间用新文本替换文本？

2 个答案: