Three types of loops are used in bash programming. While loop is one of them. Like other loops, a while loop is used to do repetitive tasks. The starting and ending block of the while loop is defined by do and done keywords in the bash script. The termin
The loop structure is one of the key components of every programming language including Bash. They are used to repeat the specified instructions against a condition. Frequently employed loop structures in Bash scripting arefor,while, anddo-while. In Bash scripting, thewhileloop functions by repeatin...
这是一个无限循环,每 0.5 秒打印出 This is an infinite while loop. Press Ctrl+C to exit out of the loop.。要退出循环,我们可以按 CTRL+C。 示例:带有 break 语句的 Bash 中的 while 循环 #!/bin/bash num=5 while [ $num -ge 0 ] do echo $num ((num--)) if [[ "$num" == '3' ...
until [ "$num" -gt 10 ]; do echo "num is $num" num=$(($num + 1)) done okay ,关于 bash 的三个常用的 loop 暂时介绍到这里。 在结束本shell十三问之前,再跟大家补充两个与 loop 有关的命令: * break * continue 这两个命令常用在复合式循环里,也就是在do ... done之间又有更进一层的...
Bash while Loop The while loop is used to performs a given set of commands an unknown number of times as long as the given condition evaluates to true. The Bash while loop takes the following form: while [CONDITION] do [COMMANDS] done Copy ...
/bin/bash for num in {1..10}; do echo $num done 如果你运行它,你应该会看到像这样的输出: $ ./for-loop.sh 1 2 3 4 5 6 7 8 9 10 你也可以使用for num in 1 2 3 4 5 6 7 8 9 10; do,但是使用括号扩展使得代码看起来更短且更智能。
Within its “do” part, we have added the “echo” statement to print the string “hello” on the shell. The “while” loop on one-line ends at the “done” keyword. Let’s save your code and exit to execute it now. Let’s run our file with the Bash command, i.e., using the...
最后要介绍的是shellscript 设计中常见的"循环"(loop)。所谓的 loop 就是 script中的一段在一定条件下反复执行的代码。 bashshell中常用的 loop 有如下三种: * for *while* until for loop 是从一个清单列表中读进变量值,并"依次"的循环执行 do 到 done 之间的命令行。 例: for v ...
1. Create a timer using the while loop Yep, you can create a timer using the while loop. Let me share the code first and then, I will explain it: #!/bin/bash seconds=10 while [ $seconds -gt 0 ]; do clear echo "Timer: $seconds seconds" ...
“`bash #!/bin/bash count=1 while [ $count -le 5 ] do echo “Loop iteration: $count” count=$((count+1)) done “` 上述脚本会输出1到5的数字,每行一个数字。 2. 读取文件内容 可以利用while循环逐行读取文件的内容,并对每行进行处理。例如,统计文件中包含特定关键字的行数: ...