深入学习Linux Shell编程指南

需积分: 9 125 浏览量更新于2024-07-20 1 收藏 2.61MB PDF 举报

"深入学习Linux Shell编程指南：《高级Bash脚本教程》（Advanced Bash Scripting Guide）是一本由Mendel Cooper编写的权威教程，适合初学者和进阶用户。该书在2014年3月10日进行了最后一次修订，标志着'公众领域'版本的发布，这意味着它完全免费且无版权限制，可供个人学习和教学使用。书中强调了实践的重要性，认为真正掌握Shell脚本编程的最佳方式就是通过编写脚本。作者假设读者对编程或脚本没有先验知识，但课程设计上快速推进，逐步引导读者达到中级至高级水平。作者以深入浅出的方式，融入丰富的UNIX知识和技巧，使其不仅是一本教材，还是一本自学手册和关于Shell脚本技术的宝典。第1章，"Shell编程!"，可能是对基础概念的介绍，包括各种Shell的工作原理、环境变量、命令解释器等，旨在为新手奠定坚实的基础。章节内容可能涵盖Shell的历史、命令行接口的使用以及基本语法。第2章，"从入门开始"，则可能会详细讲解如何设置和配置Shell环境，如bash shell的基本操作，如何创建、运行和管理脚本，以及使用常用命令和工具。这部分会教授如何处理文件和目录，以及如何编写简单的脚本来自动化日常任务。随着章节的深入，读者将学习到更复杂的主题，如条件语句、循环结构、函数定义、错误处理、文件I/O操作、管道和重定向等，这些都是高级Shell脚本的核心元素。此外，书中还包含大量实战练习和详尽注释的示例，鼓励读者积极参与，以实际操作提升技能。由于这是一本适用于课堂的教学材料，书中可能还涵盖了教学策略和评估方法，帮助教师设计有效的学习路径。最后，这本书是对Shell编程的全面探索，对于那些希望在Linux世界中深入挖掘和提高的开发者来说，无疑是一份宝贵的资源。"

bash$ cp /home/bozo/current_work/junk/* .

Copy all the "junk" files to $PWD.

"dot" character match. When matching characters, as part of a regular expression, a "dot" matches a

single character.

partial quoting [double quote]. "STRING" preserves (from interpretation) most of the special

characters within STRING. See Chapter 5.

full quoting [single quote]. 'STRING' preserves all special characters within STRING. This is a

stronger form of quoting than "STRING". See Chapter 5.

comma operator. The comma operator [16] links together a series of arithmetic operations. All are

evaluated, but only the last one is returned.

let "t2 = ((a = 9, 15 / 3))"

# Set "a = 9" and "t2 = 15 / 3"

The comma operator can also concatenate strings.

for file in /{,usr/}bin/*calc

# ^ Find all executable files ending in "calc"

#+ in /bin and /usr/bin directories.

if [ -x "$file" ]

then

echo $file

done

# /bin/ipcalc

# /usr/bin/kcalc

# /usr/bin/oidcalc

# /usr/bin/oocalc

# Thank you, Rory Winston, for pointing this out.

,, ,

Lowercase conversion in parameter substitution (added in version 4 of Bash).

escape [backslash]. A quoting mechanism for single characters.

\X escapes the character X. This has the effect of "quoting" X, equivalent to 'X'. The \ may be used to

quote " and ', so they are expressed literally.

See Chapter 5 for an in-depth explanation of escaped characters.

Filename path separator [forward slash]. Separates the components of a filename (as in

/home/bozo/projects/Makefile).

This is also the division arithmetic operator.

command substitution. The `command` construct makes available the output of command for

assignment to a variable. This is also known as backquotes or backticks.

Advanced Bash-Scripting Guide

Chapter 3. Special Characters 10

In combination with the >> redirection operator, has no effect on a pre-existing target file (: >>

target_file). If the file did not previously exist, creates it.

This applies to regular files, not pipes, symlinks, and certain special files.

May be used to begin a comment line, although this is not recommended. Using # for a comment

turns off error checking for the remainder of that line, so almost anything may appear in a comment.

However, this is not the case with :.

: This is a comment that generates an error, ( if [ $x -eq 3] ).

The ":" serves as a field separator, in /etc/passwd, and in the $PATH variable.

bash$ echo $PATH

/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/sbin:/usr/sbin:/usr/games

A colon is acceptable as a function name.

:()

{

echo "The name of this function is "$FUNCNAME" "

# Why use a colon as a function name?

# It's a way of obfuscating your code.

}

# The name of this function is :

This is not portable behavior, and therefore not a recommended practice. In fact, more recent releases

of Bash do not permit this usage. An underscore _ works, though.

A colon can serve as a placeholder in an otherwise empty function.

not_empty ()

{

} # Contains a : (null command), and so is not empty.

reverse (or negate) the sense of a test or exit status [bang]. The ! operator inverts the exit status of

the command to which it is applied (see Example 6-2). It also inverts the meaning of a test operator.

This can, for example, change the sense of equal ( = ) to not-equal ( != ). The ! operator is a Bash

keyword.

In a different context, the ! also appears in indirect variable references.

In yet another context, from the command line, the ! invokes the Bash history mechanism (see

Appendix L). Note that within a script, the history mechanism is disabled.

wild card [asterisk]. The * character serves as a "wild card" for filename expansion in globbing. By

itself, it matches every filename in a given directory.

bash$ echo *

abs-book.sgml add-drive.sh agram.sh alias.sh

Advanced Bash-Scripting Guide

Chapter 3. Special Characters 12

剩余915页未读，继续阅读

SimonVr

粉丝: 0
资源: 7

深入学习Linux Shell编程指南

linux shell学习资料

LinuxShell脚本学习基础视频

Linux认证考试辅导用书

Ubunt Linux初学者推荐用书.

Ubuntu部落：初学者推荐用书

Red Hat Enterprise Linux 5基础教程 ppt

嵌入式Linux C语言基础与实例进阶 视频 源程序 PPT

深入学习Linux Shell编程经典教程：Advanced Bash Scripting Guide

Linux系统实战：最新版本下载与学习资源

Ubuntu部落：Linux初学者指南

最新资源

嵌入式Linux C语言基础与实例进阶视频源程序 PPT