Syntax For For Loop In Linux Phote

Usage of in the bash for loop is similar to the file globbing that we use in the linux command line when we use ls command and other commands. For example, the following will display all the files and directories under your home directory. which is similar to the C for loop syntax. The following example generates 5 random number using

The syntax of a for loop from the bash manual page is. for name in word do list done The semicolons may be replaced with carriage returns, as noted elsewhere in the bash manual page quotA sequence of one or more newlines may appear in a list instead of a semicolon to delimit commands.quot. However, the reverse is not true you cannot arbitrarily replace newlines with semicolons.

In this article, we are going to focus on the for loop in BASH scripts. Depending on the use case and the problem it is trying to automate, there are a couple of ways to use loops. Simple For loop Range-based for loop Array iteration for loops C-Styled for loops Infinite for loop Simple For loop. To execute a for loop we can write the

Portability For loop syntax works consistently across most Unix-like systems, making your Bash scripts portable. Now let's look at some examples to see how for loops are used in practice. 1. Iterating Through a List of Static Values. One simple application of for loops is to iterate through a predefined list of static values.

I commonly like to use a slight variant on the standard for loop. I often use this to run a command on a series of remote hosts. I take advantage of Bash's brace expansion to create for loops that allow me to create non-numerical for loops. Example I want to run the uptime command on frontend hosts 1-5 and backend hosts 1-3

The until loop follows the same syntax as the while loop until condition do COMMANDS Done. The key difference between until loop and while loop is in the test condition. A while loop will keep running as long as the test condition is true on the flip side, an until loop will keep running as long as test condition is false!

B. quotforquot Loop Syntax for List of Elements. for item in item1 item2 item3 ..itemN do code to execute done. C. quotforquot Loop Syntax for Array. for element in quotarrquot do code to execute done. D. quotforquot Loop Syntax for Command Output. for output in LINUX_COMMAND do code to execute done Shell Script Examples in Linux Using quotfor

Use the 'Continue' statement with Bash For Loop. The 'continue' statement is a built-in command that controls how a script runs. Apart from bash scripting, it is also used in programming languages such as Python and Java. The continue statement halts the current iteration inside a loop when a specific condition is met, and then resumes

Conclusion. The for loop is a fundamental tool in Linux shell scripting, allowing for the automation of repetitive tasks. Whether you are iterating over files, numbers, or command outputs, the flexibility of for loops makes them essential for efficient scripting. Mastering for loops will significantly enhance your ability to process and manipulate data in the Linux environment.