A deep dive into common special characters in Linux

<p><img src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/article/000/000/164/171039924720129.jpg" class="lazy" alt="A deep dive into common special characters in Linux"></p> <p>Linux operating system, as a commonly used open source operating system, has strong customizability and flexibility. When using Linux systems, we often encounter the processing of various special characters. These special characters have special meanings in the command line and can implement many advanced functions. This article will delve into the common special characters in Linux and introduce their usage in detail with specific code examples. </p> <ol><li>Wildcards: </li></ol> <p>Wildcards are special characters used to match file names. Common wildcards include <code>*</code>, <code>?</code> ,<code>[]</code>wait. Here are some commonly used wildcard examples: </p> <ul> <li> <code>*</code>: Matches zero or more of any characters. </li> <li> <code>?</code>: Match any character. </li> <li> <code>[ ]</code>: Matches characters within the specified range. </li> </ul><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'># 查找以txt结尾的所有文件 ls *.txt # 查找名字以a开头，后面跟一个数字，最后是txt结尾的文件 ls a[0-9]t.txt</pre><div class="contentsignin">Copy after login</div></div><ol start="2"><li>Redirection symbols: </li></ol><p>Redirection symbols are used to control the direction of input and output. Common redirection symbols include<code>></code>, <code>>></code>, <code><</code>, etc. The following are examples of several commonly used redirection symbols: </p><ul><li><code>></code>: Redirect the output of the command to a file, overwriting the file if it already exists. </li><li><code>>></code>: Append the output of the command to the end of the file. </li><li><code><</code>: Use the file content as input to the command. </li></ul><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'># 将ls命令的输出重定向到result.txt文件中 ls > result.txt # 将echo命令的输出追加到result.txt文件末尾 echo "Hello World" >> result.txt # 从input.txt文件读取内容，并通过cat命令显示在屏幕上 cat < input.txt</pre><div class="contentsignin">Copy after login</div></div><ol start="3"><li>Pipe symbol: </li></ol><p>The pipe symbol is used to use the output of one command as the input of another command. The common pipe symbol is <code>| </code>. The following is an example of commonly used pipe symbols: </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'># 查找包含关键词"error"的日志并输出到grep命令中进行过滤 cat log.txt | grep "error"</pre><div class="contentsignin">Copy after login</div></div><ol start="4"><li>Escape symbols: </li></ol><p>Escape symbols are used to change the meaning of special characters. Common escape symbols are ` `. The following is an example of commonly used escape symbols: </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'># 创建一个文件名包含空格的文件 touch file with space.txt</pre><div class="contentsignin">Copy after login</div></div><p>Summary: </p> <p>This article introduces common special characters in Linux, including wildcards, redirection symbols, pipe symbols and escape symbols. They are explained in detail with specific code examples. Proficient in the usage of these special characters will help us perform various operations in the Linux system more efficiently. I hope this article can help readers gain a deeper understanding of the application of special characters in Linux systems. </p>

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