While Loops The other most common form of loop in the shell is the while loop. As its name suggests, it keeps on executing the code in the body of … - Selection from Shell Scripting: Expert Recipes for Linux, Bash, and More [Book]
Shell scripting, specifically Bash scripting, is a great way to automate repetitive or tedious tasks on your systems. Why type when you can schedule and run scripts in a hands-free manner? One of the many scripting constructs is the loop. A loop is a section of code that picks up data ...
while true; do echo "Running at $(date)"; ; sleep <interval in sec> ; done Explanation of the above shell script The true keyword turns the while loop into an infinite loop sincethe exit statusor condition to be checked by the while loop will always literally be true. This is follow...
Example 1: Infinite While loop in a shell script An infinite While loop means your script will run the loop commands non-stop. Infinite While loops never stop running and this occurs when the condition always turns out to be “True.” You can create an infinite While loop with the followin...
In this version of the script, we set up an endless loop (one that never terminates on itsown) by using the true command to supply an exit status to while. Since true willalways exit with a exit status of zero, the loop will never end. This is a surprisinglycommon scripting technique...
We can use awhileloop to improve the read-menu program from the previous chapter: 我们可以使用一个 while 循环,来提高前面章节的 read-menu 程序: #!/bin/bash # while-menu: a menu driven system information program DELAY=3 # Number of seconds to display results ...
AB, we hope that you will explore theDo…While…Loopconstruction with Windows PowerShell, and you will be able to use it to meet your scripting needs. You know, while I was at the Riverbanks Zoo this weekend, I saw another bear as well. If you encounter a bear while scripting...
While Loop #!/bin/bash var=1 total=0 while [ $var -lt 101 ]; do total=$((total + var)) var=$((var+1)) done echo sum is $total 注意: 1.“=”两边一定不能有空格 2. 上面
现在开始讲迭代器，迭代是指以一定的自动化程度多次重复某个过程，通常又称为循环。说的通俗点就是批量...
If Awk is already being used for other purposes, employing a shell loop to iterate through lines can be inefficient and frequently considered an antipattern. While this approach doesn't fully address the issue, it does prevent the need to execute a new instance of Awk for every iteration. ...