![]() If you followed the step correctly, you should see the following screen. The script will run with our specified arguments and use positional parameters to generate an output. Now, we will open the command line on our system and run the shell script with the following arguments./PositionalParameters.sh learning command line arguments Once we are done, we will save the script as PositionalParameters.sh and exit our text editor. #!/bin/sh echo "Script Name: $0" echo "First Parameter of the script is $1" echo "The second Parameter is $2" echo "The complete list of arguments is echo "Total Number of Parameters: $#" echo "The process ID is $$" echo "Exit code for the script: $?" This is the shell script which we plan to use for this purpose. Use nano or any preferred editor of your choice and copy the following. Now it’s time to use this knowledge for practical application of the netstat command.įor this tutorial, we will go over an example to learn how to use the command-line arguments in your shell script.įirst, we will create a shell script to demonstrate the working of all the reserved variables which we discussed in the previous section. Now we have developed an understanding of the command-line arguments in Linux. Read Command-line Arguments in Shell Scripts We use $$ to find the process ID of the current shell script, while $? can be used to print the exit code for our script. We also have and $* as wildcard characters which are used to denote all the arguments. The special character $# stores the total number of arguments. We also have some special characters which are positional parameters, but their function is closely tied to our command-line arguments. The variable $0 stores the name of the script or the command itself. Here, the first command-line argument in our shell script is $1, the second $2 and the third is $3. Bash saves these variables numerically ($1, $2, $3, … $n) The bash shell has special variables reserved to point to the arguments which we pass through a shell script. Hence, command-line arguments are an essential part of any practical shell scripting uses. They help a script identify the data it needs to operate on. How Shell Scripts Understand Command Line ArgumentsĬommand-line arguments help make shell scripts interactive for the users. In this article, we will go over the concept of command-line arguments along with their use in a shell script. Understanding the command-line arguments is essential for people who are learning shell scripting. We use command-line arguments to denote the position in memory where the command and it’s associated parameters are stored. They are also known as positional parameters in Linux. What are Command-Line Arguments?Ĭommand-line arguments are parameters that are passed to a script while executing them in the bash shell. We can use these arguments to obtain outputs and even modify outputs just like variables in shell scripts. ![]() When we pass arguments to a shell script, we can use them for local sequencing of the script. These shell scripts can receive input from the user in the form of arguments. They play a major role in automating daily tasks and creating your own commands or macros. ![]() Shell scripts are an essential tool for any Linux user. In today’s article, we’ll learn to read command-line arguments in shell scripts. Reading user input is one part of the equation.
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