What is getopt for?
getopts is a built-in Unix shell command for parsing command-line arguments. It is designed to process command line arguments that follow the POSIX Utility Syntax Guidelines, based on the C interface of getopt.
What is Optarg?
optarg indicates an optional parameter to a command line option. opterr can be set to 0 to prevent getopt() from printing error messages. optind is the index of the next element of the argument list to be process, and optopt is the command line option last matched.
How do I use Getopts in bash?
An example of how to use getopts in bash
- getopt here to get the input arguments.
- check that -s exists, if not return an error.
- check that the value after the -s is 45 or 90.
- check that the -p exists and there is an input string after.
- if the user enters ./myscript -h or just ./myscript then display help.
Is Optarg a string?
optstring is a string containing the legitimate option characters. If such a character is followed by a colon, the option requires an argument, so getopt() places a pointer to the following text in the same argv-element, or the text of the following argv-element, in optarg.
Does getopt work with-L?
Your code was actually very, very close to working. The only thing you were missing is that getopt only expects you to consume one argument after -l, and therefore continues command line parsing following the first argument to -l.
How to remove-F option from getopts?
getopts options can only take zero or one argument. You might want to change your interface to remove the -f option, and just iterate over the remaining non-option arguments usage: foo.sh -i end -d dir -s subdir file […] Show activity on this post. With the space separator you can just run through it with a basic loop.
How many arguments can be added to an option?
You can specify the minimum and the maximum number of arguments that option accepts. You can also specify that an option takes zero or more arguments (or one or more, two or more, and so on). And, of course, you can specify a fixed number of arguments: zero, one, two, and so on.
How to specify a number of values for an option?
If you want to specify any number of values for an option, you can use a simple loop to find them and stuff them into an array. For example, let’s modify the OP’s example to allow any number of -s parameters: