#!/bin/bash while true do if [ `date +%H` -ge 17 ]; then break # exit loop fi echo keep running ~/bin/process_data done … run other commands here … 总结 永远循环很容易。指定要停止循环的条件却需要花费一些额外的精力。via: networkworld.com/articl ...
In Bash scripting, thewhileloop functions by repeating a set of instructions as long as the specified condition is true. Typically, the while loop is preferred where the number of iterations is uncertain or variable. In this guide, I will explore theBash while loop, its syntax, and usage th...
for和while命令使这件事非常容易。关于相应的语法和策略,只有几件事要牢记。 使用while 最简单的永远循环之一是使用while命令,后面跟上条件true。 你不必使用诸如while [ 1 -eq 1 ]之类的逻辑或类似的测试。while true测试表示循环将一直运行,直到你使用CTRL-C停止循环、关闭终端窗口或注销为止。这是一个例子: 复...
#!/bin/bash set -euo pipefail; while true; do echo -n "Enter the word: "; IFS=$'\n\t ' read -d$'\n' -r inputword restofsentence; if [[ -n "${inputword}" && -z "${restofsentence}" ]] ; then reverse="$( rev <( echo "${inputword}" ) )"; if [[ "${reverse}...
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:
condition为true时命令1到命令3将会一直执行,知道条件为false ,例如: 1. #!/bin/bash x=1 while [ $x -le 5 ] do echo "Welcome $x times" x=$(( $x + 1 )) done 1. 2. 3. 4. 5. 6. 7. Here is a sample shell code to calculate factorial using while loop: ...
while true do echo "endless loop" done 可以在 if/then 中作占位符: #!/bin/bash condition=5 if [ $condition -gt 0 ] #gt表示greater than,也就是大于,同样有-lt(小于),-eq(等于) then : # 什么都不做,退出分支 else echo "$condition" ...
问带有if语句的Bash while循环停滞在true循环中ENPython 编程中 while 语句用于循环执行程序，即在某条件...
在bash中，变量是一个用来存储数据的实体。每个变量都有一个名称和一个值，名称是变量的 ...
The condition may be tested at the beginning, or the end of the loop. This loop generally uses a while loop construct. The infinite loop repeats the execution of a section of code forever or until an exception arises. This loop often uses a while true loop construct and is sometimes ...