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 任何条件表达式 Bash until Example 5. 监控日志文件 此示例监视日志文件的大小,一旦日志文件大小达到 2000 字节,它将获取该日志文件的副本。 $ cat monitor.sh file=/tmp/l...
InBashscripting, there are 3 types ofloops:for loop,while loop, anduntil loop. The three are used to iterate over a list of values and perform a given set of commands. In this guide, we will focus on theBash For Loopin Linux. Table of Contents Conclusion Bash For Loop Syntax As ment...
The for loop allows you to specify a list of values. A group of statements is executed for each value in the list. For loop syntax The for loop in the shell takes a list of words (strings) as an argument. The number of words in the list determines the number of times the statements...
According to the above syntax, the starting and ending block offorloop is defined bydoanddonekeywords in the bash script. The uses of different loops have shown in the next part of this tutorial. Example-1: Reading static values Create a bash file namedloop1.shwith the following script to...
Bash also offerscstylefor loopsyntax. If are from aClanguage background, then this syntax will not be new to you. Instead of iterating through a list, you will be evaluating a condition and if the condition is true, the commands within the loop will be executed. ...
The output for the for loop with command substitution as demonstrated in the above example would be: Bash For Loop: C Style Syntax The C style syntax suits users who are more accustomed to the for loop syntax in other languages like C, C++, Java, JavaScript, etc. Here is the basic synt...
Bash For Loop Syntaxfor varname in list;do command1;command2;doneorfor varname in list do command1 command2 ... doneorfor var in $(cat file1);do command1;command2;doneorfor var in $(cat file1) do command1 command2 ... doneorfor variable in ...
Syntax error: Bad for loop variable 分析: 从ubuntu 6.10 开始,ubuntu 就将先前默认的bash shell 更换成了dash shell;其表现为 /bin/sh 链接倒了/bin/dash而不是传统的/bin/bash。 allen@allen-lql ~/workspace/script $ ls -l /bin/sh lrwxrwxrwx 1 root root 4 Aug 12 14:29 /bin/sh ->dash...
可以通过ls -l /bin/*sh命令看到: 所以在使用sh命令执行脚本的时候实际使用的是 dash,而 dash 不支持这种 C 语言格式的 for 循环写法。 解决方法:使用bash代替sh运行脚本: bash test.sh
Another unique way to define the “for” loop is using the “seq” expression in it. So, open the same file and add the bash extension to it. The syntax of the “for” loop has been shown in the snap attached below. The “for” loop has started with the iterator variable “I” ...