Various Ways to Increment or Decrement Counters in Bash Incrementing/decrementing is mostly used in a loop where the user has instructed the script/program to increase/decrease value based on the given condition
Counter:998Counter:999Counter:1000 break和continue声明 break和continue语句可用于控制for循环的执行。 break声明 break语句终止当前循环,并将程序控制权传递给终止语句之后的语句。它通常用于在满足特定条件时终止循环。 在以下示例中,一旦当前迭代项等于“锂”,我们就使用if语句终止循环的执行。 forelementinHydrogen He...
The below syntax is used in a count-controlled for loop, i.e. a for-loop counter, which uses a bash arithmetic expansion. The first expression is evaluated once according to shell arithmetics rules. The second expression is evaluated each repeatedly until it evaluates to zero. Each time the...
# Update the counter file by incrementing the number it contains. perl -i -ple'++$_'counter break# valid input received, exit the loop ;; 'out') # Update the counter file by decrementing the number it contains. perl -i -ple'--$_'counter break# valid input received, exit the loop ...
A‘while’ loop will continue to execute as long as the condition in the loop remains true. When working with arrays, you can use a counter and increment it in each iteration until you’ve gone through all the elements. Here’s an example: ...
Using the ++ and -- Counter Operators Examples of the use of these operators are as follows: for increment: bash num=$((num++)) ((num++))let"num++" for decrement: bash num=$((num--)) ((num--))let"num--" In the Until loop, the counter is written like this: ...
从Bash 4开始,还可以在指定范围同时时还可以指定增量。在指定增量时语法形式是{START..END..INCREMENT}。INCREMENT表示增量。 除了使用上面的方式遍历一个范围之外,你还可以使用c语言风格的for循环达到同样的效果。 在下面的代码中,通过初始化i = 0,然后在每次迭代之前检查是否i ≤ 1000。如果为true,则打印i的当前...
# increment counter for each matched dept. case $DEPT in Accounts) ACC_LOOP=`expr $ACC_LOOP + 1` ACC="Accounts" ;; Customer) CUS_LOOP=`expr $CUS_LOOP + 1` CUS="Customer" ;; Payroll) PAY_LOOP=`expr $PAY_LOOP + 1` PAY="Payroll" ...
This style uses three expressions like C-language to specify the number of loop iterations. for((initialization;condition;increment/decrement))doShell command[s]done Example: Assume we want to write a script that may help us print a table of any user-provided number. We can do that using th...
Bash while Loop Increment and Decrement The loop structure is incomplete without the increment or decrement. There are various methods to implement increment and decrement in the while loop. Using Round Brackets (( )) UsingletCommand The simplest way to add increment or decrement is using the rou...