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...
Thus, in simple terms, a Bash While loop is used for automating commands in Bash scripting. Bash While loop example A While loop in a Bash script will trigger a series of commands to run repeatedly for as long as the condition result is “True.” Below is an example of Bash While loop...
read 命令从标准输入读取行,所以 while 循环读取标准输入,直到 EOF 发生。 until循环 until 语句在语法和功能上与 while 语句非常相似。两者之间唯一真正的区别是,当条件表达式为假时,直到语句执行其代码块,而当条件表达式为真时,while 语句执行其代码块。 syntax: until expression do commands #body of the loop ...
两者之间唯一真正的区别是,当条件表达式为假时,直到语句执行其代码块,而当条件表达式为真时,while 语句执行其代码块。 syntax:until expressiondocommands #bodyofthe loop done 在上面的 bash until 语法中: where until, do, done 是关键字 表达式 任何条件表达式 Bash until Example 5. 监控日志文件 此示例监视...
A 'for loop' is a bash programming language statement which allows code to be repeatedly executed. A for loop is classified as an iteration statement i.e. it is the repetition of a process within a bash script. Tutorial details For example, you can run UNIX command or task 5 times or ...
# Endless loop example [me@linux ~]$ while : ; do echo "infinite loop"; done infinite loop ... Using a while-loop is generally the recommended way in Bash for iterating over each line of a file or stream. See the FAQ How To Loop Over Each Lines Of A File? for an example. ...
While one can use the for loop for numbers and strings, programmers can even leverage the same to repeat over a range. For example, we will state an array - Players and iterate over each of the elements of the range. PLAYERS=('Cristiano Ronaldo' 'Lionel Messi' 'Iker Casillas') for pla...
Using a "do while" loop in bash scripting is simple. Here, ‘-le’ keywords indicate the "less than or equal" sign of a normal programming language. The following script will run until the variable's value is greater than five. #!/bin/bash echo "Do while loop example" a=1 while [...
while-loop 将运行直到表达式测试为真。will run while the expression that we test for is true. 关键字"break" 用来跳出循环。而关键字”continue”用来不执行余下的部分而直接跳到下一个循环。 for-loop表达式查看一个字符串列表 (字符串用空格分隔) 然后将其赋给一个变量: ...
will run while the expression that we test for is true. 关键字"break" 用来跳出循环。而关键字”continue”用来不执行余下的部分而直接跳到下一个循环。 for-loop表达式查看一个字符串列表 (字符串用空格分隔) 然后将其赋给一个变量: for var in ...; do ......