One of the most common arithmetic operations when writing Bash scripts is incrementing and decrementing variables. This is most often used in loops as a counter, but it can occur elsewhere in the script as well. Incrementing and Decrementing means adding or subtracting a value (usually 1), ...
Let’s create a simple shell scriptlet_cmd.shto show how we can increment an integer variable using theletcommand: $ cat let_cmd.sh #!/bin/bash COUNTER=0 printf "Initial value of COUNTER=%d\n" $COUNTER let COUNTER=COUNTER+1 printf "After 'let COUNTER=COUNTER+1', COUNTER=%d\n" $COU...
The++operator is a convenient way to increment a Bash variable using a single statement. It eliminates the need to explicitly specify the increment value because the operator increments its operand by 1 and returns the value. Use the++operator directly with the variable. Follow the steps below t...
A‘while’ loop will continue to execute as long as the condition in the loop remains true. When working with arrays, you can use a counter and increment it in each iteration until you’ve gone through all the elements. Here’s an example: fruits=('apple' 'banana' 'cherry') index=0 ...
Using the += and -= Counter Operators Examples of the use of these operators are as follows: for increment: num=$((num+=1)) ((num+=1)) let "num+=1" for decrement: num=$((num-=1)) ((num-=1)) let "num-=1" Bash example for the+=and-=counter operators in awhileloop: ...
If you have any questions or feedback, feel free to leave a comment.bash loop terminal Related Tutorials Bash Sequence Expression (Range) How to Increment and Decrement Variable in Bash (Counter) Bash until Loop Bash while Loop Bash For Loop Bash read Command Bash Exit Command and Exit Codes...
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/bin/bash## Name: test-bucket-1## Purpose:# Performs the test-bucket number 1 for Product X.# (Actually, this is a sample shell script,# which invokes some system commands# to illustrate how to construct a Bash script)## Notes:# 1) The environment variable TEST_VAR must be set# (...
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 the following code. #!/bin/bashecho"Enter a Number: "readnumberfor((j=1;j<=10;j++))...
In short, this is how I write my counter to that file: # create a variable to represent the filename COUNTER_FILE="counter.tmp" # write to the file echo "0" > $COUNTER_FILE Later in the code I increment the counter and write it to the file like this: ...