GETOPT(1) User Commands GETOPT(1)


NAME


getopt - parse command options

SYNOPSIS


set -- ` getopt optstring $ * `


DESCRIPTION


The getopts command supersedes getopt. For more information, see NOTES
below.


getopt is used to break up options in command lines for easy parsing by
shell procedures and to check for legal options. optstring is a string of
recognized option letters; see getopt(3C). If a letter is followed by a
colon (:), the option is expected to have an argument which may or may
not be separated from it by white space. The special option - is used to
delimit the end of the options. If it is used explicitly, getopt
recognizes it; otherwise, getopt generates it; in either case, getopt
places it at the end of the options. The positional parameters ($1 $2
...) of the shell are reset so that each option is preceded by a - and is
in its own positional parameter; each option argument is also parsed into
its own positional parameter.

EXAMPLES


Example 1: Processing the arguments for a command




The following code fragment shows how one might process the arguments for
a command that can take the options -a or -b, as well as the option -o,
which requires an argument:


set -- `getopt abo: $*`
if [ $? != 0 ]
then
echo $USAGE
exit 2
fi
for i in $*
do
case $i in
-a | -b) FLAG=$i; shift;;
-o) OARG=$2; shift 2;;
--) shift; break;;
esac
done


This code accepts any of the following as equivalent:


cmd -aoarg filename1 filename2
cmd -a -o arg filename1 filename2
cmd -oarg -a filename1 filename2
cmd -a -oarg -- filename1 filename2


ATTRIBUTES


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


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|CSI | enabled |
+---------------+-----------------+

SEE ALSO


Intro(1), getopts(1), getoptcvt(1), sh(1), shell_builtins(1), getopt(3C),
attributes(5)

DIAGNOSTICS


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

NOTES


getopt will not be supported in the next major release. For this release
a conversion tool has been provided, namely, getoptcvt. For more
information, see getopts(1) and getoptcvt(1).


Reset optind to 1 when rescanning the options.


getopt does not support the part of Rule 8 of the command syntax standard
(see Intro(1)) that permits groups of option-arguments following an
option to be separated by white space and quoted. For example,

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


is not handled correctly. To correct this deficiency, use the getopts
command in place of getopt.


If an option that takes an option-argument is followed by a value that is
the same as one of the options listed in optstring (referring to the
earlier EXAMPLES section, but using the following command line:

cmd -o -a filename


getopt always treats it as an option-argument to -o; it never recognizes
-a as an option. For this case, the for loop in the example shifts past
the filename argument.


January 7, 2000 GETOPT(1)