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...
add.sh: 4: Syntax error: Bad for loop variable 代码没有错误,Ubuntu为了加快开机速度,用dash取代bash。 解决的方法:取消dash,使用bash: sudo dpkg-reconfigure dash 选择No选项。
shell script 号称是程序 (program) ,但实际上, shell script 处理数据的速度上是不太够的。 因为shell script 用的是外部的指令与 bash shell 的一些默认工具,所以,他常常会去呼叫外部的函式库,因此,指令周期上面当然比不上传统的程序语言。 所以啰, shell script 用在系统管理上面是很好的一项工具,但是用在处...
in 列表是可选的,如果不用它,for 循环使用命令行的位置参数。 范例1 顺序输出当前列表中的数字: #!/bin/bash for loop in 1 2 3 4 5 do echo "The value is: $loop" done 1. 2. 3. 4. 5. 运行结果: The value is: 1 The value is: 2 The value is: 3 The value is: 4 The value i...
linux shell scripts:Syntax error: Bad for loop variable,执行脚本报错#!/bin/bashs=0for((i=1;i<=100;i++))dos=$(($s+$i))doneecho$sshadd.sh报错:add.sh:4:Syntaxerror:Badforloopvariable代码没有错误
0. 循环(loop) 今天,终于学习到循环啦～什么是循环? 循环可以不断的执行某个程序段落,直到用户设定的条件达成为止。 而根据循环的次数是否固定,又可以分为不定循环和固定循环,这篇文章里学习while do done和until do done两种不定循环。 1. while do done ...
You can have awhileloop to keep checking for that directory's existence and only write a message while the directory does not exist. If you want to do something more elaborate, you could create a script and show a more clear indication that the loop condition became true: ...
How Does Shell Script Looping Work?Shell scripts written in Bash can implement looping, or iteration, with the while, until, and for constructs. In each case, a block of code is executed repeatedly until a loop exit condition is satisfied. The script then continues on from that point. The...
(3).这是一个shell脚本算出从1到10的平方 #这个脚本有 多个写法; 第一种写法; #!/bin/bash #脚本解释程序 for i in `seq 1 10` #for循环,从1开始,每次递增1,知道10结束 do echo "$i--->$(($i*$i))" #把每次循环的值相乘,来达到算出1~10的平法的结果 done...
fruit=orange; and on the third and final iteration,fruit=pear. Once it has completed the loop, the script continues normal execution with the next command after thedonestatement. In this case, it ends by saying “Let’s make a salad!” to show that it has ended the loop, but not the...