按unix 的规范,返回状态码为 0 就是表示正常执行,其它值都表示不正常。 非要当成布尔值看待的话,可以这样想:为 0 就是正常,正常就是 true,不为 0 就是不正常,不正常就是 false。这跟其它语言 0 当 false 不同,所以特容易搞反。 但是返回什么值是程序自己决定的,一般常见 unix 程序都会仔细定义状态码。
UNIX/Linux e09330e1749e4191a9dfe441e5129f Moving ahead from our previous tutorial on arrays in shell scripts, let’s understand how we can use if-else in shell scripts. Conditional programming is an important part of any programming language because executing every single statement in our progr...
6. What is the alternative to if-else statements in shell scripting? An alternative to if-else statements in shell scripting is the case statement. The case statement allows you to match a value against multiple patterns and execute different blocks of code based on the match. Here’s an ex...
现在,许多 Linux® 和 UNIX® 都有Bash 环境,它往往还是Linux默认的shell环境。Bash拥有强大的程序设计能力,包括各种的测试文件类型的函数和其它特性,比如像大多数程序语言中的数值和字符串的比较一样。 理解各种测试,并且懂得在shell中通过元操作符表达大部分的操作,这些是成为一个强大的shell用户重要的步骤。这篇...
commonly adhere to the “one tool for one job” philosophy of UNIX generally use coding idioms, which optimize speed and size usually bare-bones, minimum red tape portability in terms of copy-paste mechanics easily convertible to analias
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As a novice in Unix shell scripting, I utilized the 'grep'method to create a filefor the given string, which is identified as delete file based . However, when trying to execute the script mentioned as script file , an error occurred indicating that there is an issue with line 10 of th...
Conditional statements help in deciding the proper execution path for operations. Unix/Linux Shell supports two conditional statements: The if...else statement The case...esac statement Control statements are used to indicate how the control is transferred during the program execution....
shell中if做比较 shell中if做比较比较两个字符串是否相等的办法是: if [ "$test"x = "test"x ]; then 这里的关键有几点: 1 使用单个等号 2 注意到等号两边各有一个空格:这是unix shell的要求 3 注意到"$test"x最后的x,这是特意安排 linux 服务器 shell 转载 精选 kissbaby0401 2013-11-26 15...
The csh shell is known for its inconsistency, as demonstrated by sources such as http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/. Scripting - how to make an if-else in csh script, I'm trying to make an if-else in csh script but it is not working: do you know why this is...