In a shell script, aforloop allows you to iterate over a set of values or a range of numbers. Here are a few examples of how to useforloops in different contexts: Example 1: Iterating Over a List of Values #!/bin/bash # List of values for item in apple banana cherry do echo "...
1.1 认识 for ... do ... done 昨天刚学过while,until的循环方式 -->Linux 之 shell script -- loop(不定循环) :符合循环条件便可以无限得循环执行指定的“程序段”,我们便称为不定循环。今天学习与不定循环相对应的for循环,这种语法则是已经知道要进行几次循环的状态。 for ... do ... done的语法结...
5. Loop through files and directories in a for loop To loop through files and directories under a specific directory, just cd to that directory, and give * in the for loop as shown below. The following example will loop through all the files and directories under your home directory. $ c...
The script then continues on from that point. The while StatementIn a while loop, the block of code between the do and done statements is executed so long as the conditional expression is true. Think of it as saying, "Execute while this condition remains true." Here's an example:...
shell也有一个真实的调试模式。如果在脚本"strangescript" 中有错误,您可以这样来进行调试: sh -x strangescript 这将执行该脚本并显示所有变量的值。 shell还有一个不需要执行脚本只是检查语法的模式。可以这样使用: sh -n your_script 这将返回所有语法错误。
1. Static values for the list after “in” keyword In the following example, the list of values (Mon, Tue, Wed, Thu and Fri) are directly given after the keyword “in” in the bash for loop. $ cat for1.sh i=1 for day in Mon Tue Wed Thu Fri ...
0. 循环(loop) 今天,终于学习到循环啦～什么是循环? 循环可以不断的执行某个程序段落,直到用户设定的条件达成为止。 而根据循环的次数是否固定,又可以分为不定循环和固定循环,这篇文章里学习while do done和until do done两种不定循环。 1. while do done ...
echo "loop num : $a" a=$(($a+1)) done a1=1 until [ "$a1" -gt 5 ] do echo "until a1:$a1" a1=$(($a1+1)) done s=0 for ((i=1;i<=100;i++)) do s=$(($s+$i)) done echo $s (1)显示多个##号脚本 #!/bin/bash #文件的开头解释语言 ...
PowerShell compiles the script code to bytecode that's interpreted. Beginning in PowerShell 3, for code that's repeatedly executed in a loop, PowerShell can improve performance by Just-in-time (JIT) compiling the code into native code....
其实作为命令语言交互式地解释和执行用户输入的命令只是shell功能的一个方面,shell还可以用来进行程序设计,它提供了定义变量和参数的手段以及丰富的程序控制结构。使用shell编程类似于DOS中的批处理文件,称为shell script,又叫shell程序或shell命令文件。 二.几种流行的shell ...