Example-1: Iterate the loop for fixed number of times. The while loop reads one line from the file in one iteration and assigned the value to the variable myvar. Syntax for using the while loop. In this example, n variable is used to keep the value of the line number of the file and while loop is used to read this file with line number. The reason for not using a while read line loop is the for the use of the if condition that wouldn't work. ) and also incremented the value of (i) inside the loop and at the end I am getting the wrong value of i, the main reason is that the usage of pipe (|) will create a new sub-shell to read the file and any operation you do within this while loop (example – i++) will get … The <(..) section enables us to specify the tail command and let Bash read from its output like a file: Record is : 1,2,20,40 Record is : 2,5,10,50 Use while loop to read file and use ${file} for both filename input into awk and as string to print I have files named with different prefixes. Kevin Barry PS Note that I used <() to generalize for the output of any command. The CONSEQUENT-COMMANDS can be … The. Bash For Loop – Second Method. Brief: This example will help you to read a file in a bash script. The for loop is not the only way for looping in Bash scripting. Read File Using Bash Script. (For whatever reason they gave it 2 names readarray and mapfile are the same thing. The bash while loop is a control flow statement that allows code or commands to be executed repeatedly based on a given condition. As the condition becomes false, the execution moves to the next line of code outside of the while loop. I wanted to know if there is any way of reading from two input files in a nested while loop one line at a time. : Bash Script A: I thought about this for a while and came up with this solution.I am far from a programmer and not great with scripting, but it get’s the job done. There are many different ways to do this, ... VALUE will be assigned local to the script, and will still be set to the value of ${line#*:} after the while loop has exited. ... Reading such a file under Linux would not produce correct results due to different line breaks. In this article, we will explain all of the kind of loops for Bash. loop command takes the following structure: while condition; do. Let us say the name of the file that we want to loop through is stored in a variable in bash. Tags bash scirpt , loop , while loop Updated on March 5, 2020 Then define the data set you want the variable to cycle through. View 5 Replies Similar Messages: General :: For Loop Or While Loop To Read The Fields Of A File? This tutorial contains two methods to read a file line by line using a shell script. Create a bash file named ‘for_list2.sh’ and add the following script.Assign a text into the variable, StringVal and read the value of this variable using for loop.This example will also work like the previous example and divide the value of the variable into words based on the space. I want to read a file real time with a while loop that is being fed by the stdout of a process (inotifywait).The output could be multiple lines, but I as soon as I've found name of a specific file in a line, I want to discard all the other lines. We need to do this with a while loop. Bash Factorial While Loop. Method 1 – Using simple loop. The general syntax for using the Bash while loop is: Following is the syntax of reading file line by line in Bash using bash while loop : Syntax To Read File line by line in Bash Scripting, following are some of the ways explained in detail. I have a file like one below. Termination condition is defined at the starting of the loop. filname=loop_thru_line_in_bash.txt In bash, we can access the content of variable using $ sign as a prefix to the variable name. 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