getopts(1)                                                         User Commands                                                        getopts(1)

NAME

       getopts - parse utility options

SYNOPSIS

       /usr/bin/getopts optstring name [ arg...]

   sh
       getopts optstring name [argument...]

   ksh
       getopts optstring name [arg...]

DESCRIPTION

   /usr/bin/getopts
       The getopts utility can be used to retrieve options and option-arguments from a list of parameters.

       Each  time  it  is invoked, the getopts utility 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. Whenever the shell is invoked, OPTIND is initialized to 1.

       When the option requires an option-argument, the getopts utility places it in the shell variable OPTARG. If no 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 processing.

       If an option-argument is missing:

         o  If the first character of optstring is a colon, the shell variable specified by name is set to the colon character and the shell vari-
            able OPTARG is set to the option character found.

         o  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 pre-
            sented 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, the getopts utility exits with a return value greater than zero; the shell variable OPTIND is set
       to the index of the first non-option-argument, where the first -- argument is considered to be an option-argument if  there  are  no  other
       non-option-arguments  appearing  before it, or the value $# + 1 if there are no non-option-arguments; the name variable is set to the ques-
       tion-mark character. 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 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  arg  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.

   sh
       getopts is a built-in Bourne shell command used to parse positional parameters and to check for valid options. See sh(1). It  supports  all
       applicable rules of the command syntax standard (see Rules 3-10, intro(1)). It should be used in place of the getopt command.

       optstring  must contain the option letters the command using getopts recognizes. If a letter is followed by a colon, the option is expected
       to have an argument, or group of arguments, which must be separated from it by white space.

       Each time it is invoked, getopts places the next option in the shell variable name and the index of the next argument to  be  processed  in
       the shell variable OPTIND. Whenever the shell or a shell script is invoked, OPTIND is initialized to 1.

       When an option requires an option-argument, getopts places it in the shell variable OPTARG.

       If an illegal option is encountered, ? is placed in name.

       When  the  end of options is encountered, getopts exits with a non-zero exit status. The special option - can be used to delimit the end of
       the options.

       By default, getopts parses the positional parameters. If extra arguments (argument ...) are given on  the  getopts  command  line,  getopts
       parses them instead.

       /usr/lib/getoptcvt reads the shell script in filename, converts it to use getopts instead of getopt, and writes the results on the standard
       output.

       So that all new commands adhere to the command syntax standard described in intro(1), they should use getopts or getopt to parse positional
       parameters and check for options that are valid for that command.

       getopts prints an error message on the standard error when it encounters an option letter not included in optstring.

       Although  the  following  command syntax rule (see intro(1)) relaxations are permitted under the current implementation, they should not be
       used because they can not be supported in future releases of the system. As in the EXAMPLES section below, -a and -b are options,  and  the
       option -o requires an option-argument.

       The following example violates Rule 5: options with option-arguments must not be grouped with other options:

       example% cmd -aboxxx filename

       The following example violates Rule 6: there must be white space after an option that takes an option-argument:

       example% cmd -ab oxxx filename

       Changing the value of the shell variable OPTIND or parsing different sets of arguments can lead to unexpected results.

   ksh
       Checks  arg  for legal options. If arg is omitted, the positional parameters are used. An option argument begins with a + or a -. An option
       not beginning with + or - or the argument - ends the options. optstring contains the letters that getopts recognizes. If a letter  is  fol-
       lowed by a :, that option is expected to have an argument. The options can be separated from the argument by blanks.

       getopts  places  the  next option letter it finds inside variable name each time it is invoked with a + prepended when arg begins with a +.
       The index of the next arg is stored in OPTIND. The option argument, if any, gets stored in OPTARG.

       A leading : in optstring causes getopts to store the letter of an invalid option in OPTARG, and to set name to ? for an unknown option  and
       to  :  when  a  required  option is missing. Otherwise, getopts prints an error message. The exit status is non-zero when there are no more
       options.

       getopts supports both traditional single-character short options and long options defined by Sun's Command Line Interface Paradigm (CLIP).

       Each long option is an alias for a short option and is specified in parentheses following its equivalent short option.   For  example,  you
       can specify the long option file as an alias for the short option f using the following script line:

       getopts "f(file)" opt

       Precede long options on the command line with -- or ++. In the example above, --file on the command line would be the equivalent of -f, and
       ++file on the command line would be the equivalent of +f.

       Each short option can have multiple long option equivalents, although this is in violation of the CLIP specification  and  should  be  used
       with caution. You must enclose each long option equivalent parentheses, as follows:

       getopts "f:(file)(input-file)o:(output-file)"

       In the above example, both --file and --input-file are the equivalent of -f, and --output-file is the equivalent of -o.

       The  variable  name  is  always set to a short option. When a long option is specified on the command line, name is set to the short-option
       equivalent.

       For a further discussion of the Korn shell's getopts built-in command, see the previous discussion in the Bourne shell (sh) section of this
       manpage.

OPERANDS

       The following operands are supported:

       optstring       A  string  containing  the  option  characters  recognised 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  need
                       not  be  recognised  if  it  is not supplied as a separate argument when getopts is invoked; see getopt(3C). 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 -. The first character  in  optstring
                       determines how getopts behaves if an option character is not known or an option-argument is missing.

       name            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.

USAGE

       Since getopts affects the current shell execution environment, it is generally provided as a shell regular built-in. If it is called  in  a
       subshell or separate utility execution environment, such as one of the following:

             (getopts abc value "$@")
              nohup getopts ...
              find . -exec getopts ... ;

       it does not affect the shell variables in the caller's environment.

       Notice  that  shell functions share OPTIND with the calling shell even though the positional parameters are changed. Functions that want to
       use getopts to parse their arguments usually want to save the value of OPTIND on entry and restore it before returning. However, there  are
       cases when a function wants to change OPTIND for the calling shell.

EXAMPLES

       Example 1: Parsing and Displaying Arguments

       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
" "$*"

       Example 2: Processing Arguments for a Command with Options

       The  following  fragment of a shell program processes the arguments for a command that can take the options -a or -b. It also processes the
       option -o, which requires an option-argument:

       while getopts abo: c
       do
             case $c in
            a | b)   FLAG=$c;;
            o)       OARG=$OPTARG;;
            ?)      echo $USAGE
               exit 2;;
            esac
       done
       shift `expr $OPTIND - 1`

       Example 3: Equivalent Code Expressions

       This code example accepts any of the following as equivalent:

       cmd -a -b -o "xxx z yy" filename
       cmd -a -b -o "xxx z yy" -- filename
       cmd -ab -o xxx,z,yy filename
       cmd -ab -o "xxx z yy" filename
       cmd -o xxx,z,yy -b -a filename

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables that affect  the  execution  of  getopts:  LANG,  LC_ALL,  LC_CTYPE,
       LC_MESSAGES, and NLSPATH.

       OPTIND          This variable is used by getopts as the index of the next argument to be processed.

       OPTARG          This variable is used by getopts to store the argument if an option is using arguments.

EXIT STATUS

       The following exit values are returned:

       0        An option, specified or unspecified by optstring, was found.

       >0       The end of options was encountered or an error occurred.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE         |      ATTRIBUTE VALUE        |
       +-----------------------------+-----------------------------+
       |Availability                 |SUNWcsu                      |
       +-----------------------------+-----------------------------+
       |Interface Stability          |Standard                     |
       +-----------------------------+-----------------------------+

SEE ALSO

       intro(1), getoptcvt(1), ksh(1), sh(1), getopt(3C), attributes(5), environ(5), standards(5)

DIAGNOSTICS

       Whenever an error is detected and the first character in the optstring operand is not a colon (:), a diagnostic message is written to stan-
       dard error with the following information in an unspecified format:

         o  The invoking program name is identified in the message. The invoking program name is the value of the shell special parameter 0 at the
            time the getopts utility is invoked. A name equivalent to

            basename "$0"

            can be used.

         o  If  an option is found that was not specified in optstring, this error is identified and the invalid option character is identified in
            the message.

         o  If an option requiring an option-argument is found, but an option-argument is not found, this error  is  identified  and  the  invalid
            option character is identified in the message.

SunOS 5.10                                                          21 Jul 2004                                                         getopts(1)