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GETOPT(1)							     GETOPT(1)

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: op-
       tions 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 pa-
       rameter shuffling and recognize optional	arguments (see section COMPAT-
       IBILITY for more	information).

       Traditional implementations of getopt(1)	are unable to cope with	white-
       space 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 re-
	      ports 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 op-
	      tions 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  shortopts
	      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.
	      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  en-
	      vironment	 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	white-
       space 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  ar-
       guments.

       A  long	option	normally  begins with `--' followed by the long	option
       name.  If the option has	a required argument, it	 may  be  written  di-
       rectly after the	long option name, separated by `=', or as the next ar-
       gument (ie. separated by	whitespace on the command line).  If  the  op-
       tion  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 re-
       quired  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 op-
       tions 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 op-
       tions string are	ignored.

RETURN CODES
       getopt returns error code 0 for succesful parsing, 1 if	getopt(3)  re-
       turns  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).

Linux				 May 31, 1997			     GETOPT(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | PARSING | OUTPUT | QUOTING | SCANNING MODES | COMPATIBILITY | RETURN CODES | EXAMPLES | ENVIRONMENT | BUGS | AUTHOR | SEE ALSO

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