如何将每行的前四个字符复制到同一行的末尾？

给定一系列类似于以下内容的行：

2001 "Some Kind of Title," Author's Name, Publication Name, 1 Mar.
2002 "Some Kind of Title," Author's Name, Publication Name, 12 Oct.
2003 "Some Kind of Title," Author's Name, Publication Name, 8 Apr.
2004 "Some Kind of Title," Author's Name, Publication Name, 3 Jun.

有没有办法我可以抓住前四个字符（年份），然后将它们复制到行的末尾，使其看起来像这样：

2001 "Some Kind of Title," Author's Name, Publication Name, 1 Mar. 2001
2002 "Some Kind of Title," Author's Name, Publication Name, 12 Oct. 2002
2003 "Some Kind of Title," Author's Name, Publication Name, 8 Apr. 2003
2004 "Some Kind of Title," Author's Name, Publication Name, 3 Jun. 2004

:% s/\v^(\d{4})(.*)$/\1\2 \1/ 

是做到这一点的一种方法

• \v 魔术选项，以避免不得不逃避分组 ()
• ^ 行首
• \d{4} 精确匹配四位数
• .* 其余的
• \1 \2 内有匹配的模式 ()

编辑：@Jair Lopez在评论中提到，正则表达式可以进一步改进：

:% s/\v^(\d{4}).*/& \1/ 

或同等学历

:% s/\v^(\d{4}).*/\0 \1/ 

• &并\0包含整个匹配的模式

有关更多阅读，请参见vimregex和regex常见问题解答

以及带有宏的解决方案：

qqyiwA <Esc>pj0q

意思是：

qq   Record the macro in the register q
yiw  Yank the text described by the text object iw (inner word): The date
A <Esc>   Append a white space to the end of the line and go back to insert mode
p    Paste the date
j0   Place your cursor on the first column of the next line (to be able to repeat the macro)
q    Stop recording

然后，您可以根据需要重播宏3@a。

编辑正如@evilsoup在评论中提到的那样，在缓冲区的所有行上执行宏的更有效方法是使用：

:%normal @q

您当然可以用描述要修改的行%的范围代替。

这是我要这样做的方式：

:%norm y4lA <C-o>p

说明：

:%norm                     "Apply the following keystrokes to every line:
       y4l                 "Yank 4 letters. You could also do 'yiw'
          A                "Add a space to the end
            <C-o>          "Do a single normal command
                 p         "Paste

如果您有权访问标准UNIX命令，则可以使用AWK：

:%!awk '{print $0" "$1}'

我认为执行此操作的现有机制更好，但是也可以使用可视块模式执行此操作。

复制日期：

gg          # Go to the top of the file
<ctrl>y     # Enter visual block mode
G           # Go to the bottom of the file
w           # Select the first word
"jy         # Copy in to the j register

填充第一行的结尾：

gg      # Top of file
A       # Append the line
        # Some spaces
<ESC>   # Return to command mode

糊：

gg 
# Move right to the length of the longest line
"jp   # Paste the block

从UNIX命令行（或Windows（如果已安装UNIX命令行工具））

sed -e "s/\(....\)\(.*\)/\1\2 \1" < inputFile > outputFile