regex - 使用 sed 对文件的行编号

Question

我想知道 sed 是否能够在对特定行进行编号时进行一些行计数工作，假设我有文件

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我想要一个将其转换为的命令：所需的输出

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这可能与sed吗？如果没有，如何在没有 bash 脚本解决方案的情况下做到这一点？

score 4 · Accepted Answer

Perl 有一个++适用于字符的便捷功能：

perl -lpe '
    /^\S/ and do {$inner_counter="a"; s/^/ ++${outer_counter} . "_ "/e}; 
    /^\s/ and s/^\s+/$& . ${inner_counter}++ . "_ "/e
' file

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score 4 · Accepted Answer

最好尝试使用awk。我假设您想对不以任何空格字符开头的行进行编号：

awk '$0 !~ /^[[:blank:]]/ { print ++i "_", $0; next } { print }' infile

它产生：

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2 回答 2