Linux while loop command is a control flow condition that will help to run the command to execute it repeatedly based on a certain condition. The execution must continue until the condition is validated to be true. The while condition started with the keyword “while” and proceeded by conditio...
do echo "This loop will run forever" sleep 1 done 要停止这种无限循环,你需要使用外部手段,如按下Ctrl+C来中断脚本的执行。 6. 读取文件内容逐行处理 while循环常用于读取文件内容,并对每一行进行处理,下面的脚本读取一个名为file.txt的文件,并将每行内容逆序打印出来: while IFS= read r line do echo "...
Thewhileloop is the best way to read a file line by line in Linux. If you need to read a file line by line and perform some action with each line – then you should use awhile read lineconstruction in Bash, as this is the most proper way to do the necessary. In this article i ...
How to use the while loop in bash 1. Create a timer using the while loop 2. Read files line by line 3. File line counter Like you, there are special variables too!An independent, reader-supported publication focusing on Linux Command Line, Server, Self-hosting, DevOps and Cloud Learning...
[me@linuxbox ~]$ while-count 1 2 3 4 5 Finished. The syntax of thewhilecommand is: while 命令的语法是: while commands; do commands; done Likeif,whileevaluates the exit status of a list of commands. As long as the exit status is zero, it performs the commands inside the loop. In...
[me@linuxbox~]$while-count12345Finished. The syntax of thewhilecommand is: while 命令的语法是: whilecommands;docommands;done Likeif,whileevaluates the exit status of a list of commands. As long as the exit statusis zero, it performs the commands inside the loop. In the script above, the...
《Linux Command Line and Shell Scripting Bible》Part 13 更多的结构化命令(for while until) for命令 基本语法格式 for var in list do commands done 也可以写成 for var in list; do commands done 读取列表中的值 1 2 3 4 5 6 7 8 9
在消除while loop命令中的延迟方面,可以采取以下几种方法: 1. 使用sleep命令:在while循环的每次迭代之间插入一个sleep命令,可以指定等待的时间,以减少循环的频率。例如,使用s...
嵌套循环( Nested Loop )其实就是多个for、while、until命令嵌套在一起 被嵌套的叫内部循环( Inner Loop ) 写一个简单的例子演示一下,如下图 image 13.6 循环处理文件数据 这个内容其实在上文中的13.1.5 更改字段分隔符小节中就有演示 这里写一个稍微复杂一点的升级版演示一下,如下图 ...
(1) 直接给出列表 (2) 整数列表: (a) {start…end} (b)(seq[start[step]]end)(3)返回列表的命令(seq[start[step]]end)(3)返回列表的命令(COMMAND) (4) 使用glob,如:.sh (5) 变量引用; $@, $ for loops c风格格式 双小括号方法,即((…))格式,也可以用于算术运算 ...