处理Linux文件的3个技巧

Linux 提供了许多用于查找、计数和重命名文件的命令。这有一些有用的选择。

Linux 提供了多种用于处理文件的命令，这些命令可以节省你的时间，并使你的工作不那么繁琐。

查找文件

当你查找文件时，find 可能会是第一个想到的命令，但是有时精心设计的 ls 命令会更好。想知道你昨天离开办公室回家前调用的脚本么？简单！使用 ls 命令并加上 -ltr 选项。最后一个列出的将是最近创建或更新的文件。

1. <span class="pln">$ </span><span class="kwd">ls</span><span class="pln"> </span><span class="pun">-</span><span class="pln">ltr </span><span class="pun">~/</span><span class="pln">bin </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">tail</span><span class="pln"> </span><span class="pun">-</span><span class="lit">3</span>
2. <span class="pun">-</span><span class="pln">rwx</span><span class="pun">------</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> shs shs </span><span class="lit">229</span><span class="pln"> </span><span class="typ">Sep</span><span class="pln"> </span><span class="lit">22</span><span class="pln"> </span><span class="lit">19</span><span class="pun">:</span><span class="lit">37</span><span class="pln"> checkCPU</span>
3. <span class="pun">-</span><span class="pln">rwx</span><span class="pun">------</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> shs shs </span><span class="lit">285</span><span class="pln"> </span><span class="typ">Sep</span><span class="pln"> </span><span class="lit">22</span><span class="pln"> </span><span class="lit">19</span><span class="pun">:</span><span class="lit">37</span><span class="pln"> ff</span>
4. <span class="pun">-</span><span class="pln">rwxrw</span><span class="pun">-</span><span class="pln">r</span><span class="pun">--</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> shs shs </span><span class="lit">1629</span><span class="pln"> </span><span class="typ">Sep</span><span class="pln"> </span><span class="lit">22</span><span class="pln"> </span><span class="lit">19</span><span class="pun">:</span><span class="lit">37</span><span class="pln"> test2</span>

像这样的命令将仅列出今天更新的文件：

1. <span class="pln">$ </span><span class="kwd">ls</span><span class="pln"> </span><span class="pun">-</span><span class="pln">al </span><span class="pun">--</span><span class="kwd">time</span><span class="pun">-</span><span class="pln">style</span><span class="pun">=+%</span><span class="pln">D </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">grep</span><span class="pln"> </span><span class="str">`date +%D`</span>
2. <span class="pln">drwxr</span><span class="pun">-</span><span class="pln">xr</span><span class="pun">-</span><span class="pln">x </span><span class="lit">60</span><span class="pln"> shs shs </span><span class="lit">69632</span><span class="pln"> </span><span class="lit">09</span><span class="pun">/</span><span class="lit">23</span><span class="pun">/</span><span class="lit">19</span><span class="pln"> </span><span class="pun">.</span>
3. <span class="pln">drwxrwxr</span><span class="pun">-</span><span class="pln">x </span><span class="lit">2</span><span class="pln"> shs shs </span><span class="lit">8052736</span><span class="pln"> </span><span class="lit">09</span><span class="pun">/</span><span class="lit">23</span><span class="pun">/</span><span class="lit">19</span><span class="pln"> bin</span>
4. <span class="pun">-</span><span class="pln">rw</span><span class="pun">-</span><span class="pln">rw</span><span class="pun">-</span><span class="pln">r</span><span class="pun">--</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> shs shs </span><span class="lit">506</span><span class="pln"> </span><span class="lit">09</span><span class="pun">/</span><span class="lit">23</span><span class="pun">/</span><span class="lit">19</span><span class="pln"> stats</span>

如果你要查找的文件可能不在当前目录中，那么 find 将比 ls 提供更好的选项，但它可能会输出比你想要的更多结果。在下面的命令中，我们不搜索以点开头的目录（它们很多一直在更新），指定我们要查找的是文件（即不是目录），并要求仅显示最近一天 （-mtime -1）更新过的文件。

1. <span class="pln">$ </span><span class="kwd">find</span><span class="pln"> </span><span class="pun">.</span><span class="pln"> </span><span class="pun">-</span><span class="kwd">not</span><span class="pln"> </span><span class="pun">-</span><span class="pln">path </span><span class="str">'*/\.*'</span><span class="pln"> </span><span class="pun">-</span><span class="pln">type f </span><span class="pun">-</span><span class="pln">mtime </span><span class="pun">-</span><span class="lit">1</span><span class="pln"> </span><span class="pun">-</span><span class="kwd">ls</span>
2. <span class="pln"> </span><span class="lit">917517</span><span class="pln"> </span><span class="lit">0</span><span class="pln"> </span><span class="pun">-</span><span class="pln">rwxrw</span><span class="pun">-</span><span class="pln">r</span><span class="pun">--</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> shs shs </span><span class="lit">683</span><span class="pln"> </span><span class="typ">Sep</span><span class="pln"> </span><span class="lit">23</span><span class="pln"> </span><span class="lit">11</span><span class="pun">:</span><span class="lit">00</span><span class="pln"> </span><span class="pun">./</span><span class="pln">newscript</span>

注意 -not 选项反转了 -path 的行为，因此我们不会搜索以点开头的子目录。

如果只想查找最大的文件和目录，那么可以使用类似 du 这样的命令，它会按大小列出当前目录的内容。将输出通过管道传输到 tail，仅查看最大的几个。

1. <span class="pln">$ </span><span class="kwd">du</span><span class="pln"> </span><span class="pun">-</span><span class="pln">kx </span><span class="pun">|</span><span class="pln"> egrep </span><span class="pun">-</span><span class="pln">v </span><span class="str">"\./.+/"</span><span class="pln"> </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">sort</span><span class="pln"> </span><span class="pun">-</span><span class="pln">n </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">tail</span><span class="pln"> </span><span class="pun">-</span><span class="lit">5</span>
2. <span class="lit">918984</span><span class="pln"> </span><span class="pun">./</span><span class="pln">reports</span>
3. <span class="lit">1053980</span><span class="pln"> </span><span class="pun">./</span><span class="pln">notes</span>
4. <span class="lit">1217932</span><span class="pln"> </span><span class="pun">./.</span><span class="pln">cache</span>
5. <span class="lit">31470204</span><span class="pln"> </span><span class="pun">./</span><span class="pln">photos</span>
6. <span class="lit">39771212</span><span class="pln"> </span><span class="pun">.</span>

-k 选项让 du 以块列出文件大小，而 x 可防止其遍历其他文件系统上的目录（例如，通过符号链接引用）。事实上，du 会先列出文件大小，这样可以按照大小排序（sort -n）。

文件计数

使用 find 命令可以很容易地计数任何特定目录中的文件。你只需要记住，find 会递归到子目录中，并将这些子目录中的文件与当前目录中的文件一起计数。在此命令中，我们计数一个特定用户（username）的家目录中的文件。根据家目录的权限，这可能需要使用 sudo。请记住，第一个参数是搜索的起点。这里指定的是用户的家目录。

1. <span class="pln">$ </span><span class="kwd">find</span><span class="pln"> </span><span class="pun">~</span><span class="pln">username </span><span class="pun">-</span><span class="pln">type f </span><span class="lit">2</span><span class="pun">></span><span class="str">/dev/</span><span class="kwd">null</span><span class="pln"> </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">wc</span><span class="pln"> </span><span class="pun">-</span><span class="pln">l</span>
2. <span class="lit">35624</span>

请注意，我们正在将上面 find 命令的错误输出发送到 /dev/null，以避免搜索类似 ~username/.cache 这类无法搜索并且对它的内容也不感兴趣的文件夹。

必要时，你可以使用 maxdepth 1 选项将 find 限制在单个目录中：

1. <span class="pln">$ </span><span class="kwd">find</span><span class="pln"> </span><span class="pun">/</span><span class="pln">home</span><span class="pun">/</span><span class="pln">shs </span><span class="pun">-</span><span class="pln">maxdepth </span><span class="lit">1</span><span class="pln"> </span><span class="pun">-</span><span class="pln">type f </span><span class="pun">|</span><span class="pln"> </span><span class="kwd">wc</span><span class="pln"> </span><span class="pun">-</span><span class="pln">l</span>
2. <span class="lit">387</span>

重命名文件

使用 mv 命令可以很容易地重命名文件，但是有时你会想重命名大量文件，并且不想花费大量时间。例如，要将你在当前目录的文件名中找到的所有空格更改为下划线，你可以使用如下命令：

1. <span class="pln">$ </span><span class="kwd">rename</span><span class="pln"> </span><span class="str">'s/ /_/g'</span><span class="pln"> </span><span class="pun">*</span>

如你怀疑的那样，此命令中的 g 表示“全局”。这意味着该命令会将文件名中的所有空格更改为下划线，而不仅仅是第一个。

要从文本文件中删除 .txt 扩展名，可以使用如下命令：