getopts(1)						      General Commands Manual							getopts(1)

NAME

       getopts - Parses utility options

SYNOPSIS

       getopts optstring name [arg...]

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       getopts:  XCU5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

OPTIONS

       None

OPERANDS

       A  string  containing  the  option  characters  recognized by the utility invoking getopts.  If a character is followed by a colon (:), the
       option is expected to have an argument, which should be supplied as a separate argument.  Applications should specify an  option  character
       and  its  option-argument as separate arguments, but getopts interprets the characters following an option character requiring arguments as
       an argument whether or not this is done. An explicit null option-argument is not recognized if it is not supplied as  a	separate  argument
       when  getopts  is invoked.  The characters question-mark (?) and colon (:) must not be used as option characters by an application. The use
       of other option characters that are not alphanumeric produces unspecified results. If the option-argument is not  supplied  as  a  separate
       argument from the option character, the value in OPTARG is stripped of the option character and the hyphen (-). The first character in opt-
       string determines getopts behavior if an option character is not known or an option-argument is missing.  The name of a shell variable that
       is set by the getopts utility to the option character that was found.

       The  getopts  utility  by  default  parses positional parameters passed to the invoking shell procedure. If args are given, they are parsed
       instead of the positional parameters.

DESCRIPTION

       The getopts utility is used to retrieve flags and flag-arguments from a list of parameters.

       Each time it is invoked, the getopts utility places the value of the next flag in the shell variable specified by the name operand and  the
       index of the next argument to be processed in the shell variable OPTIND.  Whenever the shell is invoked, OPTIND is initialized to 1.

       When  the  flag	requires  a flag-argument, the getopts utility places it in the shell variable OPTARG. If no flag is found, or if the flag
       found does not have a flag-argument, OPTARG is unset.

       If a flag character not contained in the optstring operand is found where a flag character is expected, the  shell  variable  specified	by
       name is set to the question-mark (?) character. In this case, if the first character in optstring is a colon (:), the shell variable OPTARG
       is set to the flag character found, but no output is written; otherwise, the shell variable OPTARG is unset and a diagnostic message  writ-
       ten.  This  condition  is considered to be an error detected in the way arguments were presented to the invoking application, but is not an
       error in getopts processing.

       If a flag-argument is missing, then: If the first character of optstring is a colon, the shell variable specified by name  is  set  to  the
       colon  (:)  character and the shell variable OPTARG is set to the flag character found.	Otherwise, the shell variable specified by name is
       set to the question-mark (?) character, the shell variable OPTARG is unset, and a diagnostic message is written	to  standard  error.  This
       condition  is  considered  to  be an error detected in the way arguments were presented to the invoking application, but is not an error in
       getopts processing; a diagnostic message is written as stated, but the exit status is zero.

       When the end of flags is encountered the getopts utility exits with: A return value greater than zero The shell variable OPTIND set to  the
       index  of the first non-flag-argument, where the first -- argument is considered to be a flag-argument if there are no other non-flag-argu-
       ments appearing before it, or the value $# + 1 if there are no non-flag-arguments The name variable set to the question-mark (?) character

       Any of the following identifies the end of flags: The special flag -- Finding an argument that does not begin  with  a  -  Encountering	an
       error

       The shell variables OPTIND and OPTARG are local to the caller of getopts and are not exported by default.

       The shell variable specified by the name operand, OPTIND and OPTARG affect the current shell execution environment.

       If  the	application  sets  OPTIND to the value 1, a new set of parameters can be used: either the current positional parameters or new arg
       values. Any other attempt to invoke getopts multiple times in a single shell execution environment with parameters  (positional	parameters
       or  flag operands) that are not the same in all invocations, or with an OPTIND value modified to be a value other than 1, produces unspeci-
       fied results.

NOTES

       If getopts is called in a subshell or separate utility execution environment, such as one of the following it will  not	affect	the  shell
       variables in the caller's environment:

	      (getopts	abc  value "$@") nohup getopts ...  Shell functions share OPTIND with the calling shell even though the positional parame-
	      ters are changed.  Functions that want to use getopts to parse their arguments will usually want to save	the  value  of	OPTIND	on
	      entry and restore it before returning.  However, there are cases when a function will want to change OPTIND for the calling shell.

RESTRICTIONS

       The getopts command is implemented as a shell built-in command. It is only available to users of the Korn (ksh) and POSIX shells.

       A similar capability is available to Bourne and C shell users with the getopt command.

EXIT STATUS

       The  following  exit  values  are returned: An option, specified or unspecified by optstring, was found. Successful completion.	The end of
       options was encountered or an error occurred.

EXAMPLES

       The following example script parses and displays its arguments:

       aflag= bflag= while getopts ab: name do
	    case $name in
	    a)	aflag=1;;
	    b)	bflag=1
		bval="$OPTARG";;
	    ?)	printf "Usage: %s: [-a] [-b value] args
" $0
		exit 2;;
	    esac done if [ ! -z "$aflag" ]; then
	    printf "Option -a specified
" fi if [ ! -z "$bflag" ]; then
	    printf 'Option -b "%s" specified
' "$bval" fi shift $(($OPTIND - 1)) printf "Remaining arguments are: %s
" "$*"

ENVIRONMENT VARIABLES

       The following environment variables affect the execution of getopts: Provides a default value for the internationalization  variables  that
       are  unset  or null. If LANG is unset or null, the corresponding value from the default locale is used.	If any of the internationalization
       variables contain an invalid setting, the utility behaves as if none of the variables had been defined.	 If  set  to  a  non-empty  string
       value,  overrides the values of all the other internationalization variables.  Determines the locale for the interpretation of sequences of
       bytes of text data as characters (for example, single-byte as opposed to multibyte characters in arguments and  input  files).	Determines
       the  locale  used  to  affect the format and contents of diagnostic messages written to standard error.	Determines the location of message
       catalogues for the processing of LC_MESSAGES.  On exit, this variable will contain the value of a flag-argumentm if one was  found,  other-
       wise it is unset.  This variable is used by the getopts utility as the index of the next argument to be processed.

SEE ALSO

       Commands:  getopt(1), ksh(1), sh(1p)

       Routines:  getopt(3)

       Standards:  standards(5)

																	getopts(1)