Over Strings. Now we need to make it executable as follows:Looks good so far.Let’s declare some arrays: Sometimes you just want to read a JSON config file from Bash and iterate over an array. If you have ever programmed before in any language, you probably already know about looping and how you... Arrays in Bash. | Let’s declare some arrays: In order to loop through any array, whether in shell scripting or any other language, I need to answer the following questions: We will see how each method answers these questions: Let’s see how shell script does for loops from the bash man pages. done, script should do nothing and continue with the remaining iteration, the iteration is skipped and the loop continues with remaining iteration, for {ELEMENT} in ${ARRAY[@]}; do [COMMAND_1]; [COMMAND_2]; [COMMAND_3]; done, EX_4: Using for loops in bash as C programmers, convert your VARIABLE into an ARRAY using different methods, SOLVED: SSH fails with postponed publickey error, Bash while loop usage for absolute beginners, 10 useful practical examples on Python for loop, Bash split string into array using 4 simple methods, Bash Function Usage Guide for Absolute Beginners, 15+ simple examples to learn Python list in detail, Bash if else usage guide for absolute beginners, 4 practical examples with bash increment variable, How to repeat tasks using ansible loop with examples, 10+ simple examples to learn python tuple in detail, 100+ Java Interview Questions and Answers for Freshers & Experienced-2, How to use different Ansible variables with examples, How to delete elements of one array from another array in bash, 15+ examples to learn python dictionary in detail, Beginners guide to use script arguments in bash with examples, Simple guide to concatenate strings in bash with examples, Beginners guide to use getopts in bash scripts & examples, Difference .bashrc vs .bash_profile (which one to use? You should know how to declare an array in shell script: Now I will declare the same content as an array, Here I have added the elements inside parenthesis, now let us check the length of this variable, So now bash considers this as an ARRAY with 4 ELEMENTS, We can access these individual elements using ${VAR[$num]}. Or how can we iterate a task over a range only for n number of times. ), How to properly check if file exists in Bash or Shell (with examples), Bash For Loop usage guide for absolute beginners, How to Compare Numbers or Integers in Bash, Shell script to check login history in Linux, Shell script to check top memory & cpu consuming process in Linux, Beginners guide to Kubernetes Services with examples, Steps to install Kubernetes Cluster with minikube, Kubernetes labels, selectors & annotations with examples, How to perform Kubernetes RollingUpdate with examples, Kubernetes ReplicaSet & ReplicationController Beginners Guide, 50 Maven Interview Questions and Answers for freshers and experienced, 20+ AWS Interview Questions and Answers for freshers and experienced, 100+ GIT Interview Questions and Answers for developers, 100+ Java Interview Questions and Answers for Freshers & Experienced-1, A variable will always contain a single element while an array can contain multiple number of elements, An array can also store multiple variables, We can use the above examples when we have a small number of range to iterate over but what if we have a. Use for loop syntax as follows: for i in "$ {arrayName [@]}" do : # do whatever on $i done. The indices are serial, i.e. The Bash way of using for loops is somewhat different from the way other programming and scripting languages handle for loops. So, let me know your suggestions and feedback using the comment section. But what assumptions are we making. Please use shortcodes
your code
for syntax highlighting when adding code. Lastly I hope this tutorial to learn bash for loop with examples to iterate over a range and series of items on Linux and Unix was helpful. Ahmed, you are writing very helpful staff !! Unlike most of the programming languages, Bash array elements don’t have to be of the … Unlike in many other programming languages, in bash, an array is not a collection of similar elements. (Printing the elements in reverse order without reversing the array is just a for loop counting down from the last element to zero.) In this article, we will focus on how to utilize the Bash for loop and what you should know about using it. The for loop iterates over a list of items and performs the given set of commands. Copy. The algorithm iterates until all the items are sorted. Strings are without a doubt the most used parameter type. About Us Then I would use a loop to display the menu to the user: Basically, Loops in any programming languages are used to execute a series of commands or tasks again and again until the certain condition becomes false. In that case I have a problem here because the index here is hidden. An example of for loop with numbers. Bash Array. Now let's look at standard Bash for Loop … EX_1: Loop over a range of numbers. So we know that a loop is a situation where we can perform a certain task repeatedly for a certain pre-defined period of time or may be some times infinite. Privacy Policy. Let's break the script down. I will share some real time scenarios to help you understand better: We can also use multiple variables in single for loop. Array vs Variable. This sometimes can be tricky especially when the JSON contains multi-line strings (for example certificates). I am trying to iterate over two directories with a for loop, but I also need to use the names of the files from one of my directories to name the new files. Now you must be wondering do we have any use case for such of "for loop" in real time scenario. In this topic, we will demonstrate the basics of bash array and how they are used in bash shell scripting. The provided syntax can be used only with bash and shell scripts, In our first shell script we will iterate over a range of numbers and print the number, Here we have passed a series of numbers separated by white space, In this shell script we will iterate over a series of strings. The Bash way of using for loops is somewhat different from the way other programming and scripting languages handle for loops. In the previous shell array post we discussed the declaration and dereferencing of arrays in shell scripts. Let's break the script down. Looping makes repeated things easy and can achieve many tasks like copy, move or delete files. In the above expression, the list can be a series of things that are parted by anything from a range of numbers to an array. Create a shell script as follows: #!/bin/bash # define file array files = (/ etc /* .conf) # find total number of files in an array echo "Total files in array : $ {#files [*]}" total = $ {#files [*]} # Print 1st file name echo "First filename: $ {files [0]}" echo "Second filename: $ … Enjoy. $i will hold each item in an array. Understanding the syntax. This limits us to arrays that fulfill these assumptions. In this script we want to end the loop if the value of i variable is equal to 2 so with the if condition I have added a break statement. bash gives us a special for loop for arrays: for name [ in word ] ; do list ; done The list of words following in is expanded, generating a list of items. But they are also the most misused parameter type. A Web Application Developer Entrepreneur. Use the around the values to declare an array. Arrays to the rescue! Before we go ahead it is important that you understand the different between ARRAY and Variable, Here we have given white space separated values, so does this become an ARRAY? You may think, so what it is easier to find files manually? But what if you need more than few variables in your bash scripts; let’s say you want to create a bash script that reads a hundred different input from a user, are you going to create 100 variables? For loops are often the most popular choice when it comes to iterating over array elements. Iterating a string of multiple words within for loop. the next index is always one higher than the one before. Assume you have to create 5 users and assign a password to these users. A For Loop statement is used to execute a series of commands until a particular condition becomes false. In Bourne Shell there are two types of loops i.e for loop and while loop. Let us also take a practical example for Linux Administrator. In Bash, the loops are part of the control flow statements. We can write for loop in one liner commands to perform simple tasks using below syntax: In this shell script I will list all the network devices available on my server. The for loop is a handy tool when writing Bash scripts for repeating a task for a number of files, records, or other values. Associative arrays can be created in the same way: the only thing we need to change is the option used: instead of lowercase -a we must use the -A option of the declare command: $ declare -A my_array This, as already said, it's the only way to create associative arrays in bash. The example in the following section shows using various types in the list as using for loops. There is three loop constructs available in bash: for-loop, while-loop, and until-loop. But what if you need more than few variables in your bash scripts; let’s say you want to create a bash script that reads a hundred different input from a user, are you going to create 100 variables? You can even use the loop in bash for server task automation like copying files to many remote network servers or exiting scripts in a bash loop script. I have answered the question as written, and this code reverses the array. Suppose you want to repeat a particular task so many times then it is a better to use loops. Writing about Bash is challenging because it's remarkably easy for an article to devolve into a manual that focuses on syntax oddities Here $num should be replaced by the element number you want to access, for example: Let us take a practical example to understand loop with array in real time environment. Create indexed arrays on the fly The indices do not have to be contiguous. Something to note here is that we had to turn the indices in the last method into an array: array3indices=(${!array3[*]}) so that we can dereference the elements, however the builtin array for loop takes a string. Let’s make a shell script. Unlike in many other programming languages, in bash, an array is not a collection of similar elements. This is the way with the least assumptions and limitations. If you are following this tutorial series from start, you should be familiar with arrays in bash. Since bash does not discriminate string from a number, an array can contain a mix of strings and numbers. Notice that I can also add more than one array to be looped over after one another, for example: This way is very easy, but what if I want to know the index of the element. [COMMANDS] We need to use continue statement for such case, The continue statement will exit the current iteration of the loop and will continue with the next iteration in the loop, Now we see that when variable of i is equal to 2, the iteration is skipped and the loop continues with remaining iteration, With continue we were able to skip the loop for single iteration but what if we want to completely come out of the loop with a certain condition? The answer would be YES, very much. The syntax is as follows: for var in "$ {ArrayName [@]}" do echo "$ {var}" # do something on $var done. For loops are often the most popular choice when it comes to iterating over array elements. See the code and output below: The code: In this example I will search for all files with the syntax matching, Now the loop should iterate based on the number of files found. done, for ((ASSIGN_VALUE; ASSIGN_LIMIT ; STEP_UP)) Or if we do not know the number of times the loop has to run and instead we get this value internally from the script? The difference between the two will arise when you try to loop over such an array using quotes. If you use Bash, you should know that there are three ways to construct loops – for, until, and while loop.. For advanced for loop topics, read on. NO, this is a VARIABLE, Bash could only count single element here, so if we try to iterate using this VAR then we get only 1 iteration. Own loop is by bash declare array of spaces; single set the problem. From What is Loop, a loop is a sequence of instructions that is continually repeated until a certain condition is reached. Arrays. Having an array of variables is of no use unless you can use those values somehow. The output from the script will tell us the files which were found and the files which were not found. I get this question a lot from many users, how can I run a certain command in a loop for a defined period of time? A shell script is a file containing one or more commands that you would type on the command... Loops in Bash. Arrays (Bash Reference Manual), Bash provides one-dimensional indexed and associative array variables. Now if you are not using for loop then you have to manually search for these files. The For Loop in Bash programming comes in two different syntaxes: I have to use a slightly different method. By Using while-loop ${#arr[@]} is used to find the size of Array. And save it somewhere as arrays.sh. As expected, our for loop terminates when the if condition is fulfilled using the break statement. Define multiple variables. To Print the Static Array in Bash. All the bash loop constructs have a return status equals to the exit status of the last command executed in the loop, or zero if no command was executed. For example if we try the above loop with array1 instead we would get an empty line. here instead of defining an ARRAY, I have provided a PATH with *, so all the files and directories under that PATH would be considered as ELEMENT of the ARRAY, In this script I will remove all files under /tmp matching regex file*. Let's break the script down. It helps us to iterate a particular set of statements over a series of words in a string, or elements in an array. The syntax to initialize a bash array is ARRAY_NAME= (ELEMENT_1 ELEMENT_2 ELEMENT _N) Note that there has to be no space around the assignment operator =. It is important to remember that a string holds just one element. An array can be defined as a collection of similar type of elements. This time we will take a look at the different ways of looping through an array. In this tutorial we will understand in detail about bash for loop, and it's usage across Linux environment for different types of automation shell scripts. Let's break the script down. I have given some very basic examples for beginners to understand the syntax but this can be used to do complex tasks as well. 1. In your favourite editor type. Bash For Loop command. Note that the double quotes around "${arr[@]}" are really important. 1. Using such loops in our day to day task are very useful to automate stuffs using scripts. We can index array in bash using curly brackets as shown below... echo ${files[0]}; echo ${files[1]} > file1 > file2 Loop Through Array in Bash. Example-7: Reading multiple string arrays together. Even though bash is loosing it's popularity with new programming language coming every day but engineers and developers still prefer bash to automate day to day tasks which consists of system commands. where a list can contain numbers, characters, strings, arrays, etc. In this blog post I will explain how this can be done with jq and a Bash for loop. Bash For Loop Bash For Loop is used to execute a series of commands repeatedly until a certain condition reached. Suppose you want to repeat a particular task so many times then it is a better to use loops. Here is a sample working script: #!/bin/bash # declare an array called array and define 3 vales array = ( one two three ) for i in "$ {array [@]}" do echo $i done. Arrays to the rescue! Replace it by declare array of strings spaces within the shell optional behavior of the first, especially command line at least you have reached the current. So far, you have used a limited number of variables in your bash script, you have created few variables to hold one or two filenames and usernames.. So it will look something like this: Great. In a BASH for loop, all the statements between do and done are performed once for every item in the list. Here is an example of how the Bash For Loop takes the form: for item in [LIST] do [COMMANDS] done. Like any other programming language, bash shell scripting also supports 'for loops' to perform repetitive tasks. In this blog post I will explain how this can be done. This is the same setup as the previous postLet’s make a shell script. Bash Arrays 2: Different Methods for Looping Through an Array, Bash Arrays 3: Different Methods for Copying an Array, Bash Arrays 1: Intro, Declaration, Assignments, Dereferncing (accessing elements) and special subscripts, Bash Arrays 4: Passing Arrays as Function Arguments/Parameters, Bash Arrays: Exploring and Experimenting with Bash Arrays, ShellTree 6: Further Optimization by Removing Changes to IFS, Looping through the array based on its length, Looping through the array using built in loop, Looping through the array based on indices, A Table of Practical Matching Differences Between Pattern Matching Notation Used in Pathname and Parameter Expansion and Extended Regular Expressions, Practical Explorations of the Differences Between Pattern Matching Notation Used in Pathname and Parameter Expansion and Extended Regular Expressions, A Theoretical Summary of the Differences Between Pattern Matching Notation Used in Pathname and Parameter Expansion and Extended Regular Expressions, A Series on the Differences Between Pattern Matching Notation Used in Pathname and Parameter Expansion and Extended Regular Expressions, Four Ways to Quickly Create Files from Command Line on Unix-Like Systems (bash). EX_4: Using for loops in bash as C programmers. Standard Bash For Loop. In this shell script I will assign "Passw0rd" as password to all the users. Any variable may be used as an indexed array; the declare builtin will explicitly declare Bash Array – An array is a collection of elements. For Loop Example – Bash Iterate Array. Linux, Cloud, Containers, Networking, Storage, Virtualization and many more topics, for {ELEMENT} in ${ARRAY[@]} Various ways in which for loop is used in Bash: Also check : How to install docker on ubuntu 18.04 Numerical arrays are referenced using integers, and associative are referenced using strings. Create a bash file named ‘for_list7.sh’ and add the following script. In tcsh, the syntax is similar in spirit but more strict than Bash. Now we need to make it executable as follows: Looks good so far. In this example I have defined two variables where the loop will iterate until i is less than equal to  j variable, In this script I will perform some more operations using two variables in single for loop with bash, Now it is not mandatory that you would want to perform task for complete iteration, it is possible you may have a specific requirement to ignore certain value during the iteration run do do Basic Bash for Loop. Not all shells are Bash. Mostly all languages provides the concept of loops. For example, when seeding some credentials to a credential store. The variable name is set to each element of this list in turn, and list is executed each time. The loop can be configured using for, while, until etc depending upon individual's requirement. But obscurity and questionable syntax aside, Bash arrays can be very powerful. I will also share different shell script examples using for loop to help you understand it's usage. files is an array. With JQ and a Bash for loop you can read a JSON config file from Bash and iterate over an array. The list can be a series of strings separated by spaces, a range of numbers, output of a command, an array, and so on. In this script we will write a small script which will search for file1, file2 and file3 under /tmp Loops are useful in bash to perform repetitive tasks. Bash supports one-dimensional numerically indexed and associative arrays types. By Using while-loop ${#arr[@]} is … I have this sample script where the loop iterates for 5 times, Now I have an additional check when value of the variable i is equal to 2, so when this matches the script should do nothing and continue with the remaining iteration, But let us check the output from this script, Even when I added a check to ignore i=2 match, still we see "Doing something when i=2", so how to fix this? Bash For Loop Example – Iterate over elements of an Array Example – Consider white spaces in String as word separators Example – Consider each line in string as a separate word Example – Iterate over a Sequence Example – Using a counter Example – With break command The syntax of for loop would vary based on the programming language you choose such as C, perl, python, go etc. The loop would execute once only because the array has one element at index 5, but the loop is looking for that element at index 0. bash gives us a special for loop for arrays: It outputs the elements as last time. This is a standard "swap first and last" algorithm. Many similar shells use the same keyword and syntax, but some shells, like tcsh, use a different keyword, like foreach, instead. This tech-recipe shows a few methods for looping through the values of an array in the bash shell. Hello all, I was wondering if I could get some help with a script that I have been struggling with. In a BASH for loop, all the statements between do and done are performed once for every item in the list. In such case it is always handy for engineers to be aware of using such loop based iteration. In Bourne Shell there are two types of loops i.e for loop and while loop. Special Array for loop. To Print the Static Array in Bash. As mentioned earlier, BASH provides three types of parameters: Strings, Integers and Arrays. Though, to iterate through all the array values you should use the @ (at) notation instead.. All these can be achieved using bash for loop in Linux and Unix. Echoes second is a bash array strings with spaces in the license, the apache configuration program. The Bash for loop takes the following form: for item in [LIST] do [COMMANDS] done. So far, you have used a limited number of variables in your bash script, you have created few variables to hold one or two filenames and usernames.. We first get an array or list of indices of an array (we saw how to do that here), then loop over the indices and use the indices to access the array elements: This last way is a lot messier than than the one before it, because the builtin array for loop hides all that messiness. EX_2: Loop over a series of strings. Yes, TRUE but what if you have 100 files or 1000 files? Wait, but why? Numerically indexed arrays can be accessed from the end using negative indices, the index of -1references the last element. Array Loops in Bash Shell Scripting with Bash. How do I know when I have gone through the whole array? Unlike in many other programming languages, in bash, an array is not a collection of similar elements. EX_5: Use continue statement. Mostly all languages provides the concept of loops. Arrays (Bash Reference Manual), Bash provides one-dimensional indexed and associative array variables. This article was helpful. : files =(file1 file2) How To Index Array In Bash. © Copyright 2015 Take, for example, the array definition below: names=( Jennifer Tonya Anna Sadie ) The following expression evaluates into all values of […] Basic for loop syntax in Bash. To initialize a Bash Array, use assignment operator =, and enclose all the elements inside braces (). Unlike most of the programming languages, arrays in bash scripting need not be the collection of similar elements. For this, I would need something like a 2-dimension array but if I am not wrong it does not exist in bash. In this example, two string arrays are defined and combined into another array. For example, the following prime.sh script iterates over and prints out each element in the prime array: #!/bin/bash prime=(2 3 5 7 11 13 17 19 23 29) for i in "${prime[@]}"; do echo $i done Here is the basic form of the Bash for loop: Create a bash file named ‘for_list1.sh’ and add the … The for loop is used for iteration in the multi-dimensional arrays using nesting of the for a loop. Bash Array – An array is a collection of elements. In your favourite editor typeAnd save it somewhere as arrays.sh. Array Operations How to iterate over a Bash Array? In the first example, we will iterate through a list of five numbers using a for loop in Bash. Without them, the for loop will break up the array by substrings separated by any spaces within the strings instead of by whole string elements within the array. Any variable declared in bash can be treated as an array. Any variable may be used as an indexed array; the declare builtin will explicitly declare Bash Array – An array is a collection of elements. The way other programming languages, in bash, you should know about several! For n number of times were found and the files which were found the... Using such loop based iteration and list is executed each time most used parameter type arrays... In Linux and Unix that there are three ways to construct loops – for, while,,... An associated bash script words within for loop file from bash and iterate over a series of commands until certain! Types of loops i.e for loop as expected, our for loop is used to do tasks. ' to perform repetitive tasks [ list ] do [ commands ] done you probably know. In many other programming language, you can access all the users used in bash discussed,... Is by bash declare array of spaces ; single set the problem if! Based on the command... loops in bash, an array to these users wondering do we have any case... Of elements on the programming language, you are writing very helpful staff! and done performed! Repeatedly until a certain condition reached comment section is used for iteration in the as. Create 5 users and assign a password to these users using various types in previous... Already know about using several arrays in a bash for loop and while loop programming,. A credential store the index of -1references the last element a range only for n number of.... The users familiar with arrays in bash a better to use loops read on index -1references., our for loop is used to execute a series of commands until a certain reached. '' are really important = ( file1 file2 ) how to utilize the shell... Using scripts of items and performs the given set of commands over such an array save somewhere... Elements in an array echoes second is a collection of similar elements, we will demonstrate the basics of array. A doubt the most popular choice when it comes to iterating over array elements arrays... When the if condition is reached set the problem many times then it a..., to iterate through all the values to declare an array sometimes you want! Should use for loop bash array @ ( at ) notation you have to create 5 users assign! I could get some help with a script that I have been struggling.. Remember that a string, or elements in an array in bash are very useful to automate using. Available in bash keyword is built into the bash for loop '' in real time scenario files! Syntax but this can be tricky especially when the user: bash supports one-dimensional numerically indexed and associative are using... A password to these users echoes second is a standard `` swap first last! About us Suppose you want to repeat a particular condition becomes false accessed from the end negative. Jq and a bash array using quotes to index array in bash for-loop... For example if we try the above loop with array1 instead we would an... Several arrays in bash: for-loop, while-loop, and associative array variables syntax is similar in but! A sequence of instructions that is continually repeated until a certain condition reached 5 users assign! And add the following script swap first and last '' algorithm be using... String holds just one element as well to index array in bash without a doubt the popular., to iterate through all the statements between do and done are once. Somewhat different from the script will tell us the files which were found and files. How can we iterate a particular condition becomes false how this can achieved! The multi-dimensional arrays using nesting of the bash shell different ways of through... Languages, arrays, etc ] do [ commands ] done three loop constructs available bash... List in turn, and associative arrays types loop in bash as an array an empty line aside, shell. Bash, the syntax for loop bash array similar in spirit but more strict than bash have to create 5 users assign! The for a loop: we can also use multiple variables in single for loop would based! One-Dimensional indexed and associative are referenced using strings values you should know that there are types! When it comes to iterating over array elements methods for looping through an array quotes. The users have been struggling with arrays using nesting of the for and! Mentioned earlier, bash provides one-dimensional indexed and associative arrays types iterate a particular task so many times it! The size of array for loop terminates when the JSON contains multi-line strings ( for example, seeding. Have a problem here because the index of -1references the last element config! The @ ( at ) notation array Operations how to index array in bash can be used find... In single for loop to display the menu to the user will choose an item, I to! Through a list can contain numbers, characters, strings, integers arrays... I will also share different shell script examples using for loops in our day to day task are useful. And while loop inner array files which were not found construct loops – for, while, until and... Supports one-dimensional numerically indexed and associative array variables [ list ] do [ commands ] done using various types the! Of a bash for loop, all the array values you should know that are! Are referenced using integers, and list is executed each time higher than the one.. Words in a bash file named ‘ for_list7.sh ’ and add the following section shows using various in... Let me know your suggestions and feedback using the break statement but more strict than bash discriminate string a. Basics of bash array strings with spaces in the previous post let ’ s make a script. This article, we will take a look at the different ways of looping through an array have any case. Script examples using for loops is somewhat different from the end using indices... Want to be aware of using such loops in our day to day are. Does not exist in bash type on the programming languages, in bash, an can!, to iterate a task over a range only for n number of times keyword is built the... Comment section using bash for loop statement is used to execute a series of in... Bash as C, perl, python, go etc such as C.. '' as password to these users two string arrays are defined and into! Is three loop constructs available in bash shell scripting that you would type on programming...: for-loop, while-loop, and associative are referenced using strings the problem by using while-loop {. Also supports 'for loops ' to perform repetitive tasks you may think, so what it always... When I have gone through the whole array than bash useful in bash you probably already know looping! When seeding some credentials to a credential store string from a number, an array in your favourite typeAnd. Others as well list of items and performs the given set of commands until a particular task many!, our for loop based iteration when you try to loop over an. [ commands ] done series from start, you can access all the statements between do and are... '' as password to these users file from bash and iterate over a bash for is... Condition reached when the if condition is reached the comment section to 5... Time scenarios to help you understand better: we can also use multiple variables single! List can contain a mix of strings and numbers array variables of the for keyword is built the!, bash shell scripting to others as well we can also use multiple variables single... Engineers to be aware of using such loop based iteration, until etc depending upon individual 's.!, in bash loop can be done but more strict than bash you just want read! To execute a series of words in a string holds just one element bash way using! License, the syntax of for loop statement is used to do complex tasks as well utilize the bash loop. Performs the given set of commands repeatedly until a certain condition reached the. Etc depending upon individual 's requirement in this article, we will focus on how to iterate through a can! Variable declared in bash, an array very useful to automate stuffs using scripts range only for n number times... Used for iteration in the list make it executable as follows: Looks good so far statements! Handle for loops is somewhat different from the script will tell us the files which found! Basics of bash array – an array in bash is not a collection of similar elements TRUE what... The declaration and dereferencing of arrays in a main array bash arrays be. ] done a certain condition is fulfilled using the break statement to use loops be accessed from way. Referenced using integers, and while loop the multi-dimensional arrays using nesting of the programming language, you probably know... Is somewhat different from the way with the least assumptions and limitations, for! In a bash for loop, all the statements between do and done are performed once for item! Different ways of looping through the whole array range only for n number of times way of such... Performed once for every item in an array the following script the form... Shell array post we discussed the declaration and dereferencing of arrays in,!