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..
What is Optind in bash?
$OPTIND is the number of options found by getopts . As pauljohn32 mentions in the comments, strictly speaking, OPTIND gives the position of the next command line argument. From the GNU Bash Reference Manual: getopts optstring name [args] getopts is used by shell scripts to parse positional parameters.
What is Optarg in shell script?
The getopts command is an argument to a while loop – each time through the loop, it processes the switch, and sets the $c variable to the character of the switch. You can read more about loops and case in the main tutorial. If we call this script as: dbdump.sh -s -r -d /tmp/dbdump. bin -f /tmp/files.
What is Getopts in bash?
On Unix-like operating systems, getopts is a builtin command of the Bash shell. It parses command options and arguments, such as those passed to a shell script.
How do I use Getopts in bash?
An example of how to use getopts in bashgetopt 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.
What is $1 and $2 in shell script?
$1 is the first command-line argument passed to the shell script. … If you run ./script.sh filename1 dir1, then: $0 is the name of the script itself (script.sh) $1 is the first argument (filename1) $2 is the second argument (dir1)