NAME
    getopt - parse command options (enhanced)

SYNOPSIS
    getopt optstring parameters

    getopt [options] [--] optstring parameters

    getopt [options] -o|--options optstring [options] [--] parameters

DESCRIPTION
    getopt is used  to break up (parse) options in command lines for easy
    parsing by shell procedures, and to check for legal options.  It uses
    the GNU getopt(3) routines to do this.

    The parameters getopt is called with can be divided into two parts:
    options which modify the way  getopt  will parse (options  and
    -o|--options optstring in the SYNOPSIS), and the parameters which are
    to be parsed (parameters in the SYNOPSIS). The second part will  start
    at the first non-option parameter that is not an option argument, or
    after the first occurence of `--'. If no `-o' or `--options' option is
    found in the first part, the first parameter of the second part is used
    as the short options string.

    If the environment variable GETOPT_COMPATIBLE is set, or if its  first
    parameter is not an option (does not start with a `-', this is the
    first format in the SYNOPSIS), getopt will generate output that is com-
    patible with that of other versions of getopt(1). It will still do
    parameter shuffling and recognize optional arguments (see section COM-
    PATIBILITY for more information).

    Traditional implementations of  getopt(1) are  unable  to cope with
    whitespace and other (shell-specific) special characters  in arguments
    and non-option parameters. To solve this problem, this implementation
    can generate quoted output which must once again be interpreted by the
    shell (usually by using the eval command). This has the effect of pre-
    serving those characters, but you must call getopt in a way that is no
    longer compatible with  other versions (the second or third format in
    the SYNOPSIS). To determine whether this enhanced version of getopt(1)
    is installed, a special test option (-T) can be used.

OPTIONS
    -a, --alternative
    Allow long options to start with a single `-'.

    -h, --help
    Output a small usage guide and exit succesfully. No other output
    is generated.

    -l, --longoptions longopts
    The long (multi-character) options to be recognized. More than
    one option name  may be specified at once, by separating the
    names with commas. This option may be given more than once, the
    longopts are cumulative.  Each long option name in longopts may
    be followed by one colon to indicate it has a required  argu-
    ment,and by two colons to indicate it has an optional argument.

    -n, --name progname
    The name that will be used by the  getopt(3) routines when it
    reports errors. Note that errors of getopt(1) are still reported
    as coming from getopt.

    -o, --options shortopts
    The short (one-character) options  to be  recognized. If this
    options is not found, the first parameter of getopt that does
    not start with a `-' (and is not an option argument) is used as
    the short options string.  Each short option character in short-
    opts may be followed by one colon to indicate it has a required
    argument, and by two colons to indicate it has an optional argu-
    ment. The first character of shortopts may be `+' or `-' to
    influence  the way options are parsed and output is generated
    (see section SCANNING MODES for details).

    -q, --quiet
    Disable error reporting by getopt(3).

    -Q, --quiet-output
    Do not generate normal output. Errors are still reported by
    getopt(3), unless you also use -q.

    -s, --shell shell
    Set quoting conventions to those of shell. If no -s argument is
    found, the BASH conventions are used. Valid arguments are cur-
    rently `sh' `bash', `csh', and `tcsh'.

    -u, --unquoted
    Do not quote the output. Note that whitespace and special
    (shell-dependent) characters can cause havoc in this mode  (like
    they do with other getopt(1) implementations).

    -T --test
    Test if your getopt(1) is this enhanced version or an old ver-
    sion. This generates no output, and sets the error status to 4.
    Other implementations of getopt(1), and this version if the
    environment variable GETOPT_COMPATIBLE is set, will return `--'
    and error status 0.

    -V, --version
    Output version information and exit succesfully. No other output
    is generated.

PARSING
    This section specifies the format of the second part of the parameters
    of getopt (the parameters in the SYNOPSIS). The next section (OUTPUT)
    describes the output that is generated. These parameters were typically
    the parameters a shell function was called with. Care must be taken
    that each parameter the shell function was called with corresponds to
    exactly one parameter in the parameter list of getopt (see the EXAM-
    PLES). All parsing is done by the GNU getopt(3) routines.

    The parameters are parsed from left to right. Each parameter is classi-
    fied as  a short option, a long option, an argument to an option, or a
    non-option parameter.

    A simple short option is a `-' followed by a short option character. If
    the option has  a required argument, it may be written directly after
    the option character or as the next parameter (ie. separated by whites-
    pace on  the command line). If the option has an optional argument, it
    must be written directly after the option character if present.

    It is possible to specify several short options after one `-', as long
    as all (except  possibly the last) do not have required or optional
    arguments.

    A long option normally begins with `--' followed  by the long option
    name.  If the option has a required argument, it may be written
    directly after the long option name, separated by `=', or as the next
    argument  (ie. separated by whitespace on the command line). If the
    option has an optional argument, it must be written directly after the
    long option name, separated by `=', if present (if you add the `=' but
    nothing behind it, it is interpreted as if no argument  was present;
    this is a slight bug, see the BUGS). Long options may be abbreviated,
    as long as the abbreviation is not ambiguous.

    Each parameter not starting with a `-', and not a required argument of
    a previous option, is a non-option parameter. Each parameter after a
    `--' parameter is always interpreted as a non-option parameter. If the
    environment variable POSIXLY_CORRECT is set, or if the short option
    string started with a `+', all remaining parameters are interpreted as
    non-option parameters as soon  as the first non-option parameter is
    found.

OUTPUT
    Output is generated for each element described in the previous section.
    Output is done in the same order as the elements are specified in the
    input, except for non-option parameters. Output can be done in compati-
    ble (unquoted) mode, or in such way that whitespace and other special
    characters within arguments and non-option parameters are preserved
    (see QUOTING).  When the output is processed in the shell script, it
    will seem to be composed of distinct elements that can be processed one
    by one (by using the shift command in most shell languages). This is
    imperfect in unquoted mode, as elements can be  split at unexpected
    places if they contain whitespace or special characters.

    If there are problems  parsing the parameters, for example because a
    required argument is not found or an option is not recognized, an error
    will be  reported on stderr, there will be no output for the offending
    element, and a non-zero error status is returned.

    For a short option, a single `-' and the option character are generated
    as one parameter. If the option has an argument, the next parameter
    will be the argument. If the option takes an optional argument, but
    none was found, the next parameter will be generated but be empty in
    quoting mode, but no second parameter will be generated in unquoted
    (compatible) mode.  Note that many other getopt(1) implemetations do
    not support optional arguments.

    If several short options were specified after a single `-', each will
    be present in the output as a separate parameter.

    For a long option, `--' and the full option name are generated as one
    parameter. This is done regardless whether the option was abbreviated
    or specified with a single `-' in the input. Arguments are handled as
    with short options.

    Normally, no non-option  parameters output is  generated until all
    options and their arguments have been generated. Then `--' is generated
    as a single parameter, and after it the non-option parameters in the
    order they were found, each as a separate parameter. Only if the first
    character of the short options string was a `-',  non-option parameter
    output is generated at the place they are found in the input (this is
    not supported if the first format of the SYNOPSIS is used; in that case
    all preceding occurences of `-' and `+' are ignored).

QUOTING
    In compatible mode, whitespace or 'special' characters in arguments or
    non-option parameters are not handled correctly. As the output is fed
    to the shell script, the script does not know how it is supposed to
    break the output into separate parameters. To circumvent this problem,
    this implementation offers quoting. The idea is that output is gener-
    ated with quotes around each parameter. When this output is once  again
    fed to the shell (usually by a shell eval command), it is split cor-
    rectly into separate parameters.

    Quoting is not enabled if the environment variable GETOPT_COMPATIBLE is
    set, if  the first form of the SYNOPSIS is used, or if the option `-u'
    is found.

    Different shells use different quoting conventions. You  can use the
    `-s' option to select the shell you are using. The following shells are
    currently supported: `sh', `bash', `csh' and `tcsh'.  Actually, only
    two `flavors' are distinguished: sh-like quoting conventions and csh-
    like quoting conventions. Chances are that if you use another  shell
    script language, one of these flavors can still be used.

SCANNING MODES
    The first character of the short options string may be a `-' or a `+'
    to indicate a special scanning mode. If the first calling form in the
    SYNOPSIS  is  used  they  are ignored; the  environment variable
    POSIXLY_CORRECT is still examined, though.

    If the first character is `+', or if the  environment variable
    POSIXLY_CORRECT is set, parsing stops as soon as the first non-option
    parameter (ie. a parameter that does not start with a `-') is  found
    that is not an option argument. The remaining parameters are all inter-
    preted as non-option parameters.

    If the first character is a `-', non-option parameters are outputed at
    the place where they are found; in normal operation, they are all col-
    lected at the end of output after a `--' parameter has been generated.
    Note that this `--' parameter is still generated, but it will always be
    the last parameter in this mode.

COMPATIBILITY
    This version of getopt(1) is written to be as compatible as possible to
    other versions.  Usually you can just replace them with this version
    without any modifications, and with some advantages.

    If the first character of the first parameter of getopt is not a `-',
    getopt goes into compatibility mode. It will interpret its first param-
    eter as the string of short options, and all other arguments will be
    parsed. It will still do parameter shuffling (ie. all non-option param-
    eters are outputed at the end), unless the  environment variable
    POSIXLY_CORRECT is set.

    The environment variable GETOPT_COMPATIBLE forces getopt into compati-
    bility mode. Setting both this environment variable and POSIXLY_CORRECT
    offers 100% compatibility for `difficult' programs. Usually, though,
    neither is needed.

    In compatibility mode, leading `-' and `+' characters in the  short
    options string are ignored.

RETURN CODES
    getopt returns error code 0 for succesful parsing, 1 if getopt(3)
    returns errors, 2 if it does not understand its own parameters, 3 if an
    internal  error occurs like out-of-memory, and 4 if it is called with
    -T.

EXAMPLES
    Example scripts for (ba)sh and (t)csh are provided with the getopt(1)
    distribution, and are optionally installed in /usr/local/lib/getopt or
    /usr/lib/getopt.

ENVIRONMENT
    POSIXLY_CORRECT
    This environment variable is examined by the getopt(3) routines.
    If it is set, parsing stops as soon as a parameter is found that
    is not an option or an option argument. All remaining parameters
    are  also interpreted as non-option parameters, regardless
    whether they start with a `-'.

    GETOPT_COMPATIBLE
    Forces getopt to use the first calling format as  specified in
    the SYNOPSIS.

BUGS
    getopt(3) can parse long options with optional arguments that are given
    an empty optional argument (but can not do this  for short options).
    This getopt(1) treats optional arguments that are empty as if they were
    not present.

    The syntax if you do not want any short option variables at all is not
    very intuitive (you have to set them explicitely to the empty string).

AUTHOR
    Frodo Looijaard <frodol@dds.nl>

SEE ALSO
    getopt(3), bash(1),tcsh(1).