As long as thewhileloop condition remains true, the code block within the loop is executed repeatedly.In contrast, the loop terminates if the condition evaluates to false. 3. Including User Input Into awhileLoop Condition In shell scripting, using user input as a condition for awhileloop adds...
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 ...
For other until loop examples such as integer comparison, string comparison and multiple conditions, refer to those demonstrated in the while loop.If you find this tutorial helpful, I recommend you check out the series of bash shell scripting tutorials provided by Xmodulo....
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.” ...
else: print("no,please input") 3、限制输入三次，超过三次，最近忽然发现，自己shell 中的循环...
The${#city[@]}determines the array’s size in the above code. Bash while Loop String Comparison The string comparison can be a little tricky using the while loop. In the context of shell scripting the-eqare calledinteger comparison operators. So, these operators cannot be used to compare ...
You can also use other commands likehead, tail, and pipeit to while loop. head -n 5 /etc/passwd | while read LREAD do echo ${LREAD} done Head Command Input Redirection in Linux We can redirect the content of the file towhile loopusing the Input redirection operator(<). ...
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 variablecountis created and assigned an initial value of 1. Thewhilecommand evaluates theexit status of thetestcommand. As long...
Bash While Loop Another iteration statement offered by the shell programming language is the while statement. Syntax: while expression do commands done In the above while loop syntax: while, do, done are keywords Expression is any expression which returns a scalar value ...
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