getopts.1 (2010 09)

g
getopts(1) getopts(1)
NAME
getopts - parse utility (command) options
SYNOPSIS
getopts optstring name [ arg ... ]
DESCRIPTION
getopts is used to retrieve options and option-arguments from a list of parameters.
Each time it is invoked,
getopts places the value of the next option in the shell variable specified by the
name operand and the index of the next argument to be processed in the shell variable
OPTIND. When-
ever the shell is invoked,
OPTIND is initialized to 1.
When the option requires an option-argument,
getopts places it in the shell variable
OPTARG.Ifno
option was found, or if the option that was found does not have an option-argument,
OPTARG is unset.
If an option character not contained in the optstring operand is found where an option 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 option character
found, but no output is written to standard error; otherwise, 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 process-
ing.
If an option-argument is missing:
• 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 option 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 the standard error. This condi-
tion is considered to be an error detected in the way arguments are 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 options is encountered,
getopts exits with a return value greater than zero. The shell
variable OPTIND is set to the index of the first nonoption-argument, where the first
-- argument is con-
sidered to be an option argument if there are no other non-option arguments appearing before it, or the
value
$# + 1 if there are no nonoption-arguments; the name variable is set to the question-mark charac-
ter. Any of the following identifies the end of options: the special option
--
, finding an argument that
does not begin with a
-, or 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 execu-
tion environment.
Operands
The following operands are supported:
optstring A string containing the option characters recognized by the utility invoking
getopts. If a character is followed by a colon (:), the option will be 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 will interpret the characters following an option character requiring
arguments as an argument whether or not this is done. An explicit null option-
argument need not be recognised 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
will be stripped of the option character and the -. The first character in optstring
will determine how getopts will behave if an option character is not known or an
option-argument is missing.
name The name of a shell variable that is set by
getopts to the option character that
was found.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1