The POSIX (Portable Operating System Interface) style syntax can be used with POSIX compliant shells like bash and can be used to iterate over a list of files, any sequence, or even the output of other commands. Here is the for loop syntax in bash script: for <loop_variable> in <list_...
Loop Over Directory Let’s loop over the newly createdtestdirectory and display the file names inside the directory. We’ll useforloop to do this. ~/test$forfilein*;doecho$file;done Navigate to thetestdirectory and enter the above command after$.*denotes all files inside the directory. ...
Be sure to specify different variable names for each loop. To copy the list of files file1.txt, file2.txt, and file3.txt to the web servers, use this nested loop: $ for i in file{1..3};do for x in web{0..3};do echo "Copying $i to server $x"; scp $i $x; done; ...
You can use variables inside loops to iterate over a range of elements. This is whereC-styled for loopscome in. The following example illustrates aC-style for loopthat prints out a list of numerical values from 1 to 7. #!/bin/bash n=7 for (( n=1 ; n<=$n ; n++ )); do echo...
The script defines a list of names using an array named "names". It uses a for loop to iterate over each element (name) in the array. Inside the loop, it prints a greeting message for each name using "echo". The '$name' variable holds the value of each name in each iteration of...
The basic Bash for loop goes over a list of elements, array, or can be used to execute a set of instructions in the loop body repeatedly. The following example is an implementation of for loop that is going over a list of string elements: ...
Let’s look at a simple example of a ‘for’ loop acting as a ‘foreach’ loop: for fruit in Apple Banana Cherry; do echo "I love $fruit"; done # Output: # I love Apple # I love Banana # I love Cherry In this example, the ‘for’ loop iterates over the list of fruits (...
The functionality of thewhileloop is similar toforloop. Theforloop iterates over a list of items and runs the block of code N a number of times. Here in thewhileloop, the condition is evaluated first, and if the condition is true, the block of code will be executed until the condition...
Another syntax variation of for loop also exists that is particularly useful if you are working with a list of files (or strings), range of numbers, arrays, output of a command, etc. The list/range syntax for loop takes the following form: ...
The Bash shell is an incredible tool that offers a lot of terminal ease and functionality. The for loop is a common type of loop in Bash and other programming languages. It iterates over a given list of items/options until and executes a set of commands.