Parse command line arguments in Bash
In Bash, you can use the special variables
$2, etc., to access command-line arguments passed to a script or function. These variables refer to the first, second, etc. argument passed to the script or function.
Here's an example script that uses command-line arguments:
#!/bin/bash echo "The name of the script is $0" echo "The first argument is $1" echo "The second argument is $2" echo "All the arguments are $@"
In this example,
$0 refers to the name of the script, while
$2 refer to the first and second arguments, respectively. The special variable
$@ refers to all the arguments passed to the script.
To run this script and pass in some arguments, you can use the following command:
$ ./script.sh arg1 arg2
This would output the following:
The name of the script is ./script.sh The first argument is arg1 The second argument is arg2 All the arguments are arg1 arg2
In addition to accessing individual command-line arguments, you can also use the
getopts command to parse command-line options and arguments. This is a more advanced technique, but it can be useful for scripts that accept many options and arguments. The
getopts command is beyond the scope of this answer, but you can refer to the Bash documentation for more information.
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