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注：本文为 “UNIX / 类 UNIX 系统 Shebang” 相关译文合辑概述。
英文引文，机翻未校。
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A Concise Technical Overview of UNIX/UNIX-like Systems and the Shebang Mechanism

UNIX / 类 UNIX 系统与 Shebang 机制简明概述

1. Fundamentals of UNIX and UNIX-like Operating Systems

1. UNIX 与类 UNIX 操作系统基础

1.1 Definition of the UNIX Operating System

1.1 UNIX 操作系统定义

UNIX is a multi-user operating system developed by Bell Laboratories and officially released in August 1969, with its primary design goal oriented toward supporting software development workflows.
UNIX 是一款由贝尔实验室研发、于 1969 年 8 月正式发布的多用户操作系统，其首要设计目标定位于支持软件开发工作流程。

From the perspective of trademark management and usage specifications, the term “UNIX” is a registered trademark of The Open Group. Only those operating systems that have passed the certification of this organization are authorized to use the UNIX denomination in their official naming.
从商标管理与使用规范角度而言，UNIX 一词是开放群组（The Open Group）的注册商标，只有通过该组织认证的操作系统，才有权在官方命名中使用 UNIX 这一称谓。

Within the academic literature convention, the all-uppercase or all-lowercase writing form of the term is typically employed to refer to certified UNIX systems, whereas the capitalized form “Unix” is commonly used to denote UNIX-like operating systems that implement UNIX design concepts but have not obtained official certification.
在学术文献表述惯例中，该术语的全大写或全小写书写形式通常用于指代经过认证的 UNIX 系统，而首字母大写的 Unix 则多用于指代那些实现了 UNIX 设计理念但未获得官方认证的类 UNIX 操作系统。

1.2 Key Features of the UNIX Operating System

1.2 UNIX 操作系统特性

UNIX systems exhibit a set of distinctive technical features that underpin their widespread adoption in server and embedded fields. These features include high system stability, native support for multi-user and multi-tasking operation modes, and compatibility with multi-threading technologies of modern microprocessors in contemporary versions.
UNIX 系统具备一系列支撑其在服务器与嵌入式领域广泛应用的独特技术特性，包括较高的系统稳定性、对多用户与多任务运行模式的原生支持，以及现代版本中对微处理器多线程技术的兼容能力。

In the domain of memory management, the BSD branch of the UNIX system pioneered the implementation of memory protection and virtual memory mechanisms, which have since become a standard configuration for mainstream operating systems.
在内存管理领域，UNIX 系统的 BSD 分支率先实现了内存保护与虚拟内存机制，该机制此后成为主流操作系统的标准配置。

In terms of network functionality, the BSD series was also the first to integrate IP network support modules, laying a foundation for the subsequent development of networked computing.
在网络功能层面，BSD 系列同样率先集成了 IP 网络支持模块，为网络化计算的后续发展奠定了基础。

From the perspective of development and operation, UNIX provides developers and administrators with powerful scripting capabilities, a fully functional shell environment, and a rich ecosystem of command-line tools and system daemons, enabling efficient completion of complex development and system management tasks.
从开发与运维视角来看，UNIX 为开发者与管理员提供了强大的脚本编程能力、功能完备的 Shell 环境，以及丰富的命令行工具与系统守护进程生态，能够支撑复杂开发与系统管理任务的高效完成。

The UNIX kernel serves as the pivotal component of the operating system, with built-in device driver modules. As the only system component that can directly access hardware resources, the kernel undertakes the essential functions of process scheduling, memory allocation, and hardware management.
UNIX 内核作为操作系统的关键组件，内置设备驱动模块，是唯一能够直接访问硬件资源的系统部件，承担着进程调度、内存分配与硬件管理的主要功能。

In addition to providing a unified file system access interface for user-space programs, modern UNIX kernels also integrate a complete network protocol stack, enabling native support for network communication functions.
除了为用户态程序提供统一的文件系统访问接口外，现代 UNIX 内核还集成了完整的网络协议栈，实现了对网络通信功能的原生支持。

User-space processes interact with the kernel through system calls, such as the fork call for creating new processes and the exec call for loading and executing programs. The kernel is responsible for handling these system calls, controlling the running state of processes, and managing the interaction between processes and the file system.
用户态进程通过系统调用与内核进行交互，例如用于创建新进程的 fork 调用、用于加载并执行程序的 exec 调用等。内核负责处理这些系统调用请求，控制进程的运行状态，并管理进程与文件系统之间的交互过程。

In the UNIX system architecture, access to hardware devices is abstracted as operations on special files (also known as device files) in the file system, which achieves the unification of the device access interface and the file access interface.
在 UNIX 系统架构中，对硬件设备的访问被抽象为对文件系统中特殊文件（或称设备文件）的操作，实现了设备访问接口与文件访问接口的统一。

1.3 Classification of UNIX Derivatives and UNIX-like Systems

1.3 UNIX 衍生系统与类 UNIX 系统分类

UNIX derivative systems refer to operating systems developed based on the original UNIX source code authorized by Bell Laboratories or AT&T. Typical representatives include the BSD series of systems, HP-UX developed by Hewlett-Packard, AIX developed by IBM, Solaris owned by Oracle, and the early versions of Mac OS X released by Apple.
UNIX 衍生系统指基于贝尔实验室或美国电话电报公司授权的原始 UNIX 源代码进行开发的操作系统，典型代表包括 BSD 系列系统、惠普公司研发的 HP-UX、IBM 公司推出的 AIX、甲骨文公司旗下的 Solaris，以及苹果公司发布的早期版本 Mac OS X。

UNIX-like systems, by contrast, are independent development products that do not derive from the original UNIX source code but implement the key design concepts and functional characteristics of UNIX, and comply with the POSIX (Portable Operating System Interface) standard.
与之相对，类 UNIX 系统是不源于原始 UNIX 源代码、但实现了 UNIX 关键设计理念与功能特性，且遵循可移植操作系统接口（POSIX）标准的独立开发产物。

Typical examples of such systems include Linux and QNX, which have gained wide recognition in the market due to their high compatibility and flexibility.
该类系统的典型示例包括 Linux 与 QNX，二者凭借较高的兼容性与灵活性获得了市场的广泛认可。

The BSD system is a special case in the classification of UNIX-related systems: it was initially developed based on the source code of Bell Laboratories, but later underwent a complete rewrite by a loose community of developers, which made it completely independent of the original copyrighted code and evolved into a free and open-source operating system that is highly compatible with UNIX.
BSD 系统在 UNIX 相关系统分类中属于特例：它最初基于贝尔实验室的源代码进行开发，后续由松散的开发者社区完成了完全重写，从而彻底脱离了受版权保护的原始代码，演变为一款与 UNIX 高度兼容的自由开源操作系统。

In terms of architectural design, UNIX-like systems share several common characteristics: compliance with the POSIX standard to ensure the portability of application programs; adoption of a modular design structure, with a clear separation between the kernel layer and the user layer; and adherence to the design philosophy of “everything is a file”, which abstracts hardware devices, processes, and network sockets into file objects to achieve a unified access interface.
在架构设计层面，类 UNIX 系统具备若干共同特征：遵循 POSIX 标准，以保障应用程序的可移植性；采用模块化设计结构，内核层与用户层界限清晰；秉持“一切皆文件”的设计理念，将硬件设备、进程、网络套接字等抽象为文件对象，实现统一的访问接口。

1.4 Fundamental Differences Between UNIX and Windows Operating Systems

1.4 UNIX 与 Windows 操作系统的根本差异

Microsoft Windows operating systems, due to fundamental differences in their design philosophy and technical architecture, cannot be directly compared with UNIX and UNIX-like systems in terms of key functionality and application scenarios.
微软 Windows 操作系统由于设计理念与技术架构的根本性差异，在关键功能与应用场景上无法与 UNIX 及类 UNIX 系统进行直接对比。

Windows was initially designed for single-user desktop application scenarios, and its key architecture underwent a transformation with the release of the Windows NT version. This transformation involved the unofficial porting of technical elements from the OpenVMS operating system, and since then, its key architecture has not undergone fundamental changes.
Windows 最初面向单用户桌面应用场景进行设计，其关键架构在 Windows NT 版本发布时经历了一次改造，改造过程中融入了对 OpenVMS 操作系统技术元素的非官方移植，且自此之后其关键架构未发生根本性变化。

From the perspective of system security mechanisms, the Windows operating system does not implement the Super User mechanism that is prevalent in UNIX systems. In addition, most system files can be directly accessed and modified through the graphical user interface, which is one of the important reasons why Windows systems are more vulnerable to malware and virus attacks compared with UNIX systems.
从系统安全机制角度来看，Windows 操作系统未实现 UNIX 系统中普遍采用的超级用户（Super User）机制，且多数系统文件可通过图形用户界面直接进行访问与修改，这是 Windows 系统相较于 UNIX 系统更易遭受恶意软件与病毒攻击的重要原因之一。

In contrast, OpenVMS, as a high-end server operating system, has a stable architecture and strong security performance, and its design concepts have exerted a certain influence on the development of the Windows NT kernel.
与之相对，OpenVMS 作为一款高端服务器操作系统，架构稳定且安全性能较强，其设计理念对 Windows NT 内核的发展产生了一定影响。

2. The Shebang Mechanism in UNIX-like Systems

2. 类 UNIX 系统中的 Shebang 机制

2.1 Definition and Primary Purpose of Shebang

2.1 Shebang 的定义与主要用途

The shebang, represented by the character sequence #!, is a special syntax element unique to script files in UNIX-like operating systems. It is usually located in the first line of the script file and serves as a directive for the operating system kernel to identify the script interpreter.
Shebang 由字符序列 #! 表示，是类 UNIX 操作系统中脚本文件特有的特殊语法元素，通常位于脚本文件的第一行，作用是作为操作系统内核识别脚本解释器的指令标识。

The primary purpose of the shebang is to specify the interpreter program that should be used to execute the script. When a user attempts to directly execute a script file with executable permissions from the command line, the operating system kernel reads the first line of the file. If the line starts with the #! character sequence, the kernel parses the interpreter path following the sequence and invokes the corresponding interpreter program to execute the content of the script file.
Shebang 的主要用途是指定用于执行脚本的解释器程序，当用户从命令行尝试直接执行一个具备可执行权限的脚本文件时，操作系统内核会读取该文件的第一行内容，若该行以 #! 字符序列开头，内核将解析序列后的解释器路径，并调用对应的解释器程序执行脚本文件内容。

This mechanism enables users to run scripts written in different programming languages without manually specifying the interpreter program each time, thereby simplifying the script execution process and improving development efficiency.
该机制使得用户能够运行以不同编程语言编写的脚本文件，而无需每次手动指定解释器程序，进而简化脚本执行流程，提升开发效率。

2.2 Syntax Specifications of Shebang

2.2 Shebang 的语法规范

The shebang must be placed in the first line of the script file, and there can be no leading spaces or other characters before the #! character sequence; otherwise, the operating system kernel will not recognize it as a valid interpreter directive.
Shebang 必须置于脚本文件的第一行，且 #! 字符序列前不得存在前置空格或其他字符，否则操作系统内核将无法将其识别为有效的解释器指令。

The standard syntax format of the shebang is as follows: #!/path/to/interpreter [optional parameters], where /path/to/interpreter represents the absolute path of the interpreter program, and the optional parameters are used to specify the running mode of the interpreter.
Shebang 的标准语法格式为 #!/path/to/interpreter [可选参数]，其中 /path/to/interpreter 表示解释器程序的绝对路径，可选参数用于指定解释器的运行模式。

Common examples of shebang syntax (supplemented from the second document) are as follows:
以下是常见的 Shebang 语法示例（从第二篇文档补充）：

#!/bin/bash – Bash shell interpreter
#!/bin/bash——Bash Shell 解释器
#!/usr/bin/python3 – Python 3 interpreter
#!/usr/bin/python3——Python 3 解释器
#!/usr/bin/perl – Perl interpreter
#!/usr/bin/perl——Perl 解释器
#!/bin/sh – POSIX-compliant shell
#!/bin/sh——遵循 POSIX 标准的 Shell
#!/usr/bin/env ruby – Ruby interpreter
#!/usr/bin/env ruby——Ruby 解释器
#!/usr/bin/env node – Node.js runtime
#!/usr/bin/env node——Node.js 运行时
#!/usr/bin/php – PHP CLI
#!/usr/bin/php——PHP 命令行解释器

It is worth noting that adding a space between the #! character sequence and the interpreter path is allowed in most UNIX-like systems, and this writing method does not affect the recognition of the shebang by the kernel.
值得注意的是，在多数类 UNIX 系统中，#! 字符序列与解释器路径之间添加空格是被允许的，且该写法不会影响内核对 Shebang 的识别。

Using #!/usr/bin/env interpreter is a common practice as it allows the system to find the interpreter in the user’s PATH, making the script more portable across different environments.
使用 #!/usr/bin/env interpreter 的写法是一种通用实践，该方式会让系统在用户的环境变量 PATH 中查找解释器程序，从而提升脚本在不同环境下的可移植性。

2.3 Working Mechanism of Shebang Across Different Operating Systems

2.3 Shebang 在不同操作系统中的工作机制

In Linux and traditional UNIX systems (such as FreeBSD and OpenBSD), the kernel directly parses the shebang line. After identifying the #! character sequence, it extracts the interpreter path and parameters, invokes the corresponding interpreter program through the exec system call, and passes the script file path as a parameter to the interpreter, which then reads and executes the script content.
在 Linux 与传统 UNIX 系统（如 FreeBSD、OpenBSD）中，内核直接对 Shebang 行进行解析，识别 #! 字符序列后提取解释器路径与参数，通过 exec 系统调用唤起对应的解释器程序，并将脚本文件路径作为参数传递给解释器，由解释器读取并执行脚本内容。

There are differences in the default path of the interpreter program between different UNIX-like systems. For example, the default path of the Bash interpreter in most Linux distributions is /bin/bash, while in FreeBSD, the Bash interpreter is usually installed in the /usr/local/bin/bash path.
不同类 UNIX 系统之间存在解释器程序默认路径的差异，例如多数 Linux 发行版中 Bash 解释器的默认路径为 /bin/bash，而在 FreeBSD 系统中，Bash 解释器通常安装于 /usr/local/bin/bash 路径下。

To improve the portability of scripts across different systems, it is recommended to use the #!/usr/bin/env interpreter writing method. The env program will search for the path of the specified interpreter in the system’s PATH environment variable, thereby avoiding script execution failures caused by inconsistent interpreter paths.
为提升脚本在不同系统间的可移植性，推荐使用 #!/usr/bin/env interpreter 的写法，env 程序会在系统的 PATH 环境变量中搜索指定解释器的路径，从而避免因解释器路径不一致导致的脚本执行失败问题。

In macOS, as a UNIX-like system based on the Darwin kernel, the shebang mechanism works in the same way as in Linux. However, due to changes in the default shell configuration in newer versions of macOS, the path of the Bash interpreter may need to be manually specified as /usr/local/bin/bash after manual installation.
macOS 作为基于 Darwin 内核的类 UNIX 系统，其 Shebang 机制的工作方式与 Linux 一致，但由于新版 macOS 中默认 Shell 配置的变更，Bash 解释器的路径在手动安装后可能需要指定为 /usr/local/bin/bash。

The Windows operating system does not natively support the shebang mechanism. The CMD command prompt and PowerShell do not recognize the #! character sequence as an interpreter directive. When running shell scripts in the Windows environment, users need to rely on emulation tools such as WSL (Windows Subsystem for Linux) or Git Bash. In these emulated environments, the shebang mechanism will work in the same way as in the native UNIX-like system.
Windows 操作系统原生不支持 Shebang 机制，CMD 命令提示符与 PowerShell 均不会将 #! 字符序列识别为解释器指令。在 Windows 环境中运行 Shell 脚本时，用户需要依赖 Windows 子系统 Linux（WSL）或 Git Bash 等模拟工具，在这些模拟环境中，Shebang 机制将以与原生类 UNIX 系统相同的方式工作。

2.4 Scope of Application and Limitations of Shebang

2.4 Shebang 的适用范围与局限性

The shebang mechanism is not applicable to all executable programs; it can only be used in conjunction with interpreter programs that can read and parse script file content.
Shebang 机制并非适用于所有可执行程序，仅能与能够读取并解析脚本文件内容的解释器程序搭配使用。

Typical supported interpreter types include script interpreters such as Bash, Python, Perl, Ruby, and Node.js. These interpreters can accept script file paths as parameters and execute the code logic in the files according to their own syntax rules.
典型的支持类型包括 Bash、Python、Perl、Ruby、Node.js 等脚本解释器，这类解释器能够接受脚本文件路径作为参数，并根据自身语法规则执行文件中的代码逻辑。

In contrast, pure binary executable programs (such as ls, rm, and cat in UNIX systems) and interactive programs (such as ssh and vim) cannot be used as shebang-specified interpreters. This is because these programs do not have the ability to parse script content and will throw an exec format error when invoked through the shebang mechanism.
与之相对，纯二进制可执行程序（如 UNIX 系统中的 ls、rm、cat 等）与交互式程序（如 ssh、vim 等）无法作为 Shebang 指定的解释器，原因在于这类程序不具备解析脚本内容的能力，通过 Shebang 机制调用时会抛出 exec format error 错误。

The application of the shebang mechanism is subject to several limitations in practical use, which are specifically manifested in the following aspects:
Shebang 机制在实际使用中存在若干局限性，具体表现为以下几个方面：

Path length limitation
路径长度限制
The operating system kernel has a fixed-size buffer for parsing the shebang line, with a typical size of 128 or 256 bytes. If the total length of the interpreter path and optional parameters exceeds the buffer size, the kernel will fail to parse the directive correctly, resulting in script execution failure.
操作系统内核用于解析 Shebang 行的缓冲区大小固定，典型值为 128 字节或 256 字节。若解释器路径与可选参数的总长度超出缓冲区大小，内核将无法正确解析该指令，进而导致脚本执行失败。
Parameter quantity limitation
参数数量限制
Most UNIX-like system kernels only support passing a single set of parameters to the interpreter through the shebang line. For example, the writing method #!/bin/bash -x can work normally, but the writing method #!/bin/bash -x -e that contains multiple parameters may not be recognized correctly by the kernel in some systems, resulting in only part of the parameters taking effect.
多数类 UNIX 系统内核仅支持通过 Shebang 行向解释器传递一组参数，例如 #!/bin/bash -x 的写法能够正常工作，但包含多个参数的 #!/bin/bash -x -e 写法在部分系统中可能无法被内核正确识别，导致仅部分参数生效。
Path compatibility limitation
路径兼容性限制
Hard-coded interpreter paths (such as #!/bin/bash) may not exist in different UNIX-like systems or different versions of the same system. This inconsistency in paths will lead to the error message “No such file or directory” when the script is executed across systems.
硬编码的解释器路径（如 #!/bin/bash）在不同类 UNIX 系统或同一系统的不同版本中可能不存在，这种路径的不一致性会导致脚本在跨系统执行时出现“文件或目录不存在”的错误提示。
Permission limitation
权限限制
The interpreter program specified by the shebang must have executable permissions for the current user. If the user does not have the permission to execute the interpreter program, the operating system will refuse to run the script and throw a “Permission denied” error.
Shebang 指定的解释器程序必须对当前用户具备可执行权限，若用户无该解释器程序的执行权限，操作系统将拒绝运行脚本，并抛出“权限拒绝”错误。
Cross-platform compatibility limitation
跨平台兼容性限制
As mentioned earlier, the Windows operating system does not natively support the shebang mechanism, and scripts containing shebang directives need to rely on third-party emulation tools to run in the Windows environment, which increases the complexity of cross-platform deployment of scripts.
如前文所述，Windows 操作系统原生不支持 Shebang 机制，包含 Shebang 指令的脚本在 Windows 环境中运行需依赖第三方模拟工具，这增加了脚本跨平台部署的复杂度。

2.5 Best Practices for Using Shebang

2.5 Shebang 的使用最佳实践

To maximize the effectiveness of the shebang mechanism and avoid common errors, developers should follow the following best practices when writing scripts:
为充分发挥 Shebang 机制的作用并规避常见错误，开发者在编写脚本时应遵循以下最佳实践：

Prioritize the #!/usr/bin/env writing method for portability
优先使用 #!/usr/bin/env 写法以提升可移植性
For scripts that need to be run across multiple UNIX-like systems, using the writing method #!/usr/bin/env interpreter (such as #!/usr/bin/env python3) can effectively solve the problem of inconsistent interpreter paths. The env program will search for the interpreter in the system’s PATH environment variable, ensuring that the script can find the correct interpreter in different environments.
对于需要在多个类 UNIX 系统中运行的脚本，采用 #!/usr/bin/env interpreter（如 #!/usr/bin/env python3）的写法可有效解决解释器路径不一致的问题，env 程序会在系统的 PATH 环境变量中搜索解释器，确保脚本在不同环境中都能找到正确的解释器。
Set correct executable permissions for scripts
为脚本设置正确的可执行权限
After writing the script, the user needs to use the chmod +x script_name command to add executable permissions to the script file. Only when the script has executable permissions can the operating system kernel parse the shebang line and invoke the interpreter to execute the script.
脚本编写完成后，用户需使用 chmod +x script_name 命令为脚本文件添加可执行权限，只有当脚本具备可执行权限时，操作系统内核才会解析 Shebang 行并调用解释器执行脚本。
Avoid overriding the shebang-specified interpreter
避免覆盖 Shebang 指定的解释器
Although users can manually specify the interpreter to run the script through commands such as bash script.sh, this approach may lead to inconsistencies between the actual running environment of the script and the expected environment, resulting in syntax errors or functional abnormalities. Unless for testing purposes, it is not recommended to override the interpreter specified by the shebang line.
尽管用户可以通过 bash script.sh 等命令手动指定解释器运行脚本，但这种方式可能导致脚本的实际运行环境与预期环境不一致，进而引发语法错误或功能异常。除非用于测试目的，否则不建议覆盖 Shebang 行指定的解释器。
Use parameter flags appropriately to improve script debuggability
合理使用参数选项以提升脚本可调试性
Adding appropriate parameter flags to the shebang line can improve the debuggability of the script. For example, #!/bin/bash -x enables the debug mode of the Bash shell, which prints each command executed by the script to the terminal, facilitating developers to trace and locate errors.
在 Shebang 行中添加适当的参数选项可提升脚本的可调试性，例如 #!/bin/bash -x 可启用 Bash Shell 的调试模式，将脚本执行的每条命令打印至终端，方便开发者追踪定位错误。

3. Comment Specifications for Shell Scripts

3. Shell 脚本的注释规范

3.1 Types and Writing Methods of Comments

3.1 注释的类型与写法

In Shell script development, comments are an important means of code documentation, which play a key role in improving code readability and maintainability. Shell scripts support two main types of comments: single-line comments and multi-line (block) comments.
在 Shell 脚本开发中，注释是代码文档化的重要手段，对提升代码可读性与可维护性起着关键作用。Shell 脚本支持两种主要注释类型：单行注释与多行（块级）注释。

Single-line comments
单行注释
Single-line comments are implemented using the # character. Any text following the # character on the same line will be treated as a comment by the interpreter and will not be executed. Single-line comments are suitable for adding short descriptions to code lines, such as explaining the function of a command or the purpose of a variable.
单行注释通过 # 字符实现，同一行中 # 字符后的所有文本都会被解释器视为注释内容，不会被执行。单行注释适用于为代码行添加简短说明，例如解释一条命令的功能或一个变量的用途。

Typical examples include:
典型示例包括：
```
# This is a single-line comment
echo "Hello, World!"  # This command outputs a greeting message
```
Multi-line comments
多行注释
Shell scripts do not natively support a dedicated syntax for multi-line comments. Developers can simulate multi-line comments by adding the # character at the beginning of each line, which is suitable for adding detailed descriptions of complex code blocks or the overall function of the script.
Shell 脚本原生不支持专用的多行注释语法，开发者可通过在每一行开头添加 # 字符的方式模拟实现多行注释，该方式适用于为复杂代码块或脚本整体功能添加详细说明。

Typical examples include:
典型示例包括：
```
# This is a block comment
# that explains the key function of the script
# it is used to automate the backup of system files
```
In addition, developers can also use the : ' ... ' syntax to implement block comments. The colon : represents a null command in the Shell, and the content enclosed in single quotes will be treated as a string parameter and will not be executed. This method is suitable for commenting out large sections of code during the debugging process.
此外，开发者还可使用 : ' ... ' 语法实现块级注释，冒号 : 在 Shell 中表示空命令，单引号包裹的内容会被视为字符串参数，不会被执行。该方法适用于调试过程中注释掉大段代码。

Typical examples include:
典型示例包括：
```
: '
This is a block comment implemented using the colon and single quote syntax
it can contain multiple lines of text without adding a # character to each line
'
```

3.2 Best Practices for Writing Comments

3.2 注释的编写最佳实践

To ensure the quality of script comments, developers should follow the following best practices:
为确保脚本注释的质量，开发者应遵循以下最佳实践：

Comment for clarity, not redundancy
注释以清晰为目标，避免冗余
Comments should be used to explain complex logic or non-intuitive code, and should not repeat the obvious function of the code. For example, adding the comment # Increment the variable x by 1 to the code x=$((x + 1)) is redundant, while adding a comment to a complex conditional judgment statement to explain its design logic is meaningful.
注释应用于解释复杂逻辑或非直观的代码，不应重复代码的明显功能。例如为代码 x=$((x + 1)) 添加注释 # 将变量 x 加 1 属于冗余行为，而为复杂的条件判断语句添加注释解释其设计逻辑则具备实际意义。
Explain the “why” rather than the “what”
解释“为什么”而非“是什么”
The key value of comments lies in explaining the design intent and reasoning behind the code, rather than describing the execution process of the code. For example, the comment # Check if the backup directory exists to avoid file writing failures is more valuable than the comment # Check the existence of the directory.
注释的关键价值在于解释代码背后的设计意图与推理过程，而非描述代码的执行步骤。例如注释 # 检查备份目录是否存在，避免文件写入失败 比注释 # 检查目录是否存在 更具价值。
Keep comments synchronized with code updates
保持注释与代码更新同步
When modifying the code logic, developers must update the corresponding comments in a timely manner. Outdated comments that are inconsistent with the code will mislead subsequent maintainers and reduce the maintainability of the code.
当修改代码逻辑时，开发者必须及时更新对应的注释内容，与代码不一致的过时注释会误导后续维护人员，降低代码的可维护性。
Write standardized header comments
编写规范的头部注释
A standardized header comment should be added at the beginning of the script, which includes the script’s function, author, creation date, usage method, and dependent environment. This helps users quickly understand the basic information of the script without reading the entire code.
应在脚本开头添加规范的头部注释，内容包括脚本功能、作者、创建日期、使用方法及依赖环境，帮助用户在不阅读完整代码的情况下快速了解脚本的基本信息。

Typical examples include:
典型示例包括：
```
#!/bin/bash
# Script Name: system_backup.sh
# Function: Automatically back up important system files to a remote server
# Author: Anonymous
# Creation Date: 2025-01-01
# Usage: ./system_backup.sh [backup_directory]
```
Maintain a consistent comment style
保持一致的注释风格
Throughout the script development process, a unified comment style should be maintained, such as using consistent indentation for multi-line comments and placing line-end comments at a fixed position. A consistent style can improve the overall readability of the code.
在整个脚本开发过程中，应保持统一的注释风格，例如多行注释使用一致的缩进、行尾注释置于固定位置等，统一的风格可提升代码的整体可读性。

3.3 Common Errors and Solutions in Comment Writing

3.3 注释编写中的常见错误与解决方法

Developers often encounter the following common errors when writing comments, and corresponding solutions are provided below:
开发者在编写注释时经常遇到以下常见错误，现给出对应的解决方法：

Forgetting to close block comments
忘记闭合块级注释
When using the : ' ... ' syntax to write block comments, forgetting to add the closing single quote will cause the subsequent code to be treated as a comment, resulting in script execution failure. The solution is to check the comment block carefully after writing to ensure that the opening and closing symbols are paired correctly.
使用 : ' ... ' 语法编写块级注释时，忘记添加闭合单引号会导致后续代码被视为注释内容，进而引发脚本执行失败。解决方法是编写完成后仔细检查注释块，确保起止符号配对正确。
Incorrect placement of comments
注释位置错误
Placing comments in inappropriate positions (such as inserting comments in the middle of a command line) may disrupt the code structure or even cause syntax errors. The solution is to place comments either above the code line to explain the function of the code, or at the end of the code line (with a proper space from the code) to avoid affecting code execution.
将注释置于不恰当的位置（如在命令行中间插入注释）可能破坏代码结构，甚至引发语法错误。解决方法是将注释置于代码行上方以解释代码功能，或置于代码行末尾（与代码保持适当空格），避免影响代码执行。
Retaining commented-out code in production environments
在生产环境中保留被注释的代码
During the debugging process, developers often comment out part of the code temporarily, but retaining these commented-out code segments in the production environment will increase the redundancy of the script and affect readability. The solution is to delete all temporarily commented-out code before deploying the script to the production environment, or use version control tools to manage different versions of the code.
调试过程中，开发者常会临时注释掉部分代码，但在生产环境中保留这些被注释的代码段会增加脚本的冗余度，影响可读性。解决方法是将脚本部署到生产环境前，删除所有临时注释的代码，或使用版本控制工具管理不同版本的代码。

4. Conclusion

4. 结论

UNIX and UNIX-like systems, with their stable architecture, powerful multi-user/multi-tasking capabilities, and standardized design philosophy, have become the cornerstone of server and embedded computing fields. The shebang mechanism, as a key component of script execution in UNIX-like systems, provides a simple and efficient way to specify script interpreters, which is crucial for improving the portability and execution efficiency of scripts.
UNIX 及类 UNIX 系统凭借稳定的架构、强大的多用户/多任务能力与规范化的设计理念，成为服务器与嵌入式计算领域的基石。Shebang 机制作为类 UNIX 系统中脚本执行的关键组件，提供了一种简洁高效的脚本解释器指定方式，对提升脚本的可移植性与执行效率至关重要。

Mastering the syntax specifications, working mechanisms, and best practices of the shebang is a basic requirement for developers engaged in UNIX-like system development. Meanwhile, following standardized comment writing specifications can significantly improve the readability and maintainability of Shell scripts, reducing the cost of team collaboration and subsequent maintenance.
掌握 Shebang 的语法规范、工作机制与最佳实践，是从事类 UNIX 系统开发的开发者的基本要求。同时，遵循标准化的注释编写规范，可显著提升 Shell 脚本的可读性与可维护性，降低团队协作与后续维护的成本。

In practical application, developers should select appropriate shebang writing methods and comment styles according to specific application scenarios, and avoid common technical errors, so as to ensure the stability, portability and maintainability of scripts in complex operating environments.
在实际应用中，开发者应根据具体应用场景选择合适的 Shebang 写法与注释风格，规避常见技术错误，从而确保脚本在复杂运行环境中的稳定性、可移植性与可维护性。