Let’s break down what’s going on in the Bash script you just created. Bash executes programs in order from the first line in your file to the last line. Theexprcommand can be used toevaluateBashexpressions. An expression is just a valid string of Bash code that, when run, produces a...
The $LINENO contains the line number in the script or shell function currently executing. ### Example script ### Filename: example-debug #!/usr/bin/env bash debug() { echo "Func BASH_SOURCE: ${!BASH_SOURCE[@]} ${BASH_SOURCE[@]}" echo "Func BASH_LINENO: ${!BASH_LINENO[@]} $...
We’ll write a one-stop script that leverages a few different command line utilities to help us out here. First, our script will callfuserto report the processes using the file. Then it’ll usepsto get those processes’ ID numbers and, after asking us to confirm what we want to do, ...
Create a file named ‘function_example.sh’ and add the following code. You can call any function by name only without using any bracket in bash script. #!/bin/bash function F1() { echo 'I like bash programming' } F1 Run the file with bash command. $ bash function_example.sh Go ...
Inside the function: Declare a local variable 'num' to store the argument passed to the function. Declare another local variable 'result' and initialize it to 1. Check if 'num' is negative. If it is, we print an error message and exit the script. ...
We can write functions in bash scripts as in a normal programming language and use them inside script files whenever we want. Here, we use an array of guests and welcome each with a greeting message. We can call this bash function by name once we use it inside a script. #!/bin/bash...
It is often used when debugging a script in conjunction with the bash environment variables $BASH_LINENO and $BASH_SOURCE. If you define a function with a name similar to an existing builtin or command, you will need to use the builtin or command keyword to call the original command ...
Outside the function, we call "greet()" with the argument "Alice". You can replace "Alice" with any name you want to greet. 2. Addition Function: Write a Bash script that defines a function called add that takes two numbers as arguments and prints their sum. ...
Another example is to try to access a directory through NFS where$HOMEis mounted from an NFS server: /usr/bin/find$HOME-typef-name'*.csv'-print-fprint/tmp/report.txt And you discover hours later that the NFS mount point is stale and your script is stuck. ...
The function prints a simple message when it is called. #!/bin/bash #The way to declare and call the bash function #has been shown in this script #Define a simple function function testFunc { echo "It is a testing function." } #Call the function testFunc Output: The following output...