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
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 syntax. Example: Explicit example:
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...
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 done 在上面的 bash until 语法中: where until, do, done 是关键字 表达式 任何...
Infinite for loop can be created with empty expressions, such as: #!/bin/bashfor(( ; ; ))doecho"infinite loops [ hit CTRL+C to stop]"done Conditional exit with break You can do early exit with break statement inside the for loop. You can exit from within a FOR, WHILE or UNTIL lo...
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 ...
In this example, the break statement will skip the while loop when user enters -1, otherwise it will keep adding two numbers: #!/bin/bashwhile:doread-p"Enter two numnbers ( - 1 to quit ) : "a bif[$a-eq-1]thenbreakfians=$((a + b))echo$ansdone ...
# Endless loop example [me@linux ~]$ 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...
elseif and or df -h 返回文件的使用情况 六、循环(Loop) while until until 使用 For循环 依次读names变量,空格隔开 限制For循环范围 添加步长 break 1>&2,标准输出并标准输出error Reference:https://ryanstutorials.net/bash-scripting-tutorial.php