在perl中编辑文件内容 [英] edit file contents in perl

问题描述

我想读取输入文件，然后删除与正则表达式匹配的行.并保存了该行的文件.

I would like to read an input file and then delete a line if it matches my regex. and have the file saved without that line.

我写了

open(my $fh, '<:encoding(UTF-8)', $original_file_path or die "Could not open file $original_file_path $!";

while (my $line = <$fh> ) {
    chomp $line;
    if ($line ~=/myregex/){
        delete line from file
    }
}

谢谢

推荐答案

您可以使用-i标志来修改文件 .

You can modify a file in place by using -i flag.

在您的情况下，一个简单的班轮就可以了:

In your case, a simple one liner would do:

perl -i -ne 'print unless /myregex/' the_name_of_your_file

如PerlDuck所述，如果您希望保留原始文件的副本，则可以:在-i标志后添加扩展名，例如-i.bak或-i~，然后原始文件将与此保留在一起.扩展名之后.

As mentioned by PerlDuck, if you wish to keep a copy the original file, it's possible: add an extension after the -i flag, like -i.bak or -i~, and then original file will be kept with this extension after its name.

您可以在 perlrun 上找到有关就地文件修改的更多信息.

You can find more information about inplace file modification on perlrun.

请注意，如果您使用的是Windows (MS-DOS)，则需要指定备份文件的扩展名，以后可以随意删除.请参阅此

Note that if you are using Windows (MS-DOS), you will need to specify an extension for the backup file, that you are free to delete afterward. See this link.

通过将$^I设置为不同于undef的值，可以在脚本中获得相同的行为.例如:

You can obtain the same behavior in a script by setting $^I to a value different than undef. For instance:

#!/usr/bin/perl
use strict;
use warnings 'all';

{
    local @ARGV = ( $original_file_path );
    local $^I = ''; # or set it to something else if you want to keep a backup
    while (<>) {
        print unless /myregex/
    }
}

我已经使用过local @ARGV，所以如果您在@ARGV中已经有了某些东西，就不会造成任何麻烦.如果@ARGV为空，那么push @ARGV, $original_file_path也可以.

I've used local @ARGV so if you already had something in @ARGV, it won't cause any troubles. If @ARGV was empty, then push @ARGV, $original_file_path would be fine too.

但是，如果您要在脚本中做更多的事情，您可能会希望使用完整脚本而不是单行脚本.在这种情况下，您应该阅读输入文件，然后将要保留的行打印到另一个文件，然后将第二个文件move复制到第一个文件.

However, if you have more stuff to do in your script, you might prefer a full script over a one-liner. In that case, you should read your input file, and print the lines you want to keep to another file, then move the second file to the first.

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