getoptcvt(1)
NAME
getoptcvt - convert to getopts to parse command options
SYNOPSIS
/usr/lib/getoptcvt [-b] filename
/usr/lib/getoptcvt
DESCRIPTION
/usr/lib/getoptcvt reads the shell script in filename, con-
verts it to use getopts instead of getopt, and writes the
results on the standard output.
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 syn-
tax standard (see Rules 3-10, intro(1)). It should be used
in place of the getopt command. (See the NOTES section
below.) The syntax for the shell's built-in getopts command
is:
getopts optstring name [ argument...]
optstring must contain the option letters the command using
getopts will recognize; 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, ? will be placed in
name.
When the end of options is encountered, getopts exits with a
non-zero exit status. The special option -- may 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.
So that all new commands will 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 (see the NOTES section
below).
OPTIONS
The following option is supported:
- b Makes the converted script portable to earlier
releases of the UNIX system. /usr/lib/getoptcvt modi-
fies the shell script in filename so that when the
resulting shell script is executed, it determines at
run time whether to invoke getopts or getopt.
EXAMPLES
Example 1: Processing the arguments for a command
The following fragment of a shell program 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 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 2: Equivalent code expressions
This code 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: LC_CTYPE,
LC_MESSAGES, and NLSPATH.
OPTIND
This variable is used by getoptcvt as the index of the
next argument to be processed.
OPTARG
This variable is used by getoptcvt to store the argu-
ment 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 attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcsu |
|_____________________________|_____________________________|
| CSI | enabled |
|_____________________________|_____________________________|
SEE ALSO
intro(1), getopts(1), sh(1), shell_builtins(1), getopt(3C),
attributes(5)
DIAGNOSTICS
getopts prints an error message on the standard error when
it encounters an option letter not included in optstring.
NOTES
Although the following command syntax rule (see intro(1))
relaxations are permitted under the current implementation,
they should not be used because they may not be supported in
future releases of the system. As in the EXAMPLES section
above, -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 may lead to unexpected results.
Man(1) output converted with
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