Command xgetopts

Name

xgetopts parses command line options

xgetopts runs the internal shell command option processor (Options) and emits the result as an XML document.
This is useful to be able to parse arguments from within shell scripts in a form similar to internal commands.

Options

a,argindex	Exit with argument index
o,optdef optstring	Option string
c,command cmdname	Command name
p,passthrough optstring	pass through options
[+]s,serialize	Add (+ do not add) standard serialization options to optstring
[+]ps=pass-serialize	Add (+ do not add) standard serialization options to passthrough
noargs	Do no output additional arguments
novalues	Do not output argument values

optstring A string containing the allowed options seperated by "," described below
args 0 or more arguments to be parsed using the optstring, typically $*

optstring

optstring is a single string describing the available options. It take the form of option_def "," option_def ...
Each "option_def" is the option name, optionally followed by "=longname" optionally followed by ":" or ":+".

If "=longname" is used then "longname" is an alias for the option.
If the option is followed by ":" the the option requires a value which is taken from the next argument.
If the option is followed by ":+" then the option can be specified multiple times and a list of values is produced.

If no -o or -p is given then the first argument is the optstring.

If -p is specified then an additional optstring (which should be a subset of the main optstring) is used as a "pass through". All arguments which match the passthrough optstring are serialized as is and remaining arguments are ignored. This is useful for a command to 'pass through' known arguments to another command.

if -novalues is specified then the character content of values are not output. This is useful for parameters which are not serializable or may be very large.

if -noargs is specified then the args element is omitted.

if -a is specified then the exit code is the relative position of the first non-option argument. This allows options to be parsed then remaining arguments shifted into $1 ... $N by using "shift $?"

Examples

Example

xgetopts "a=all,b:,c:+"  -all -c c1 -c c2  arg1 arg2

Result

<xgetopts>
   <options>
	  <option name="a"/>
	  <option name="c">
		 <value>c1</value>
		 <value>c2</value>
	  </option>
   </options>
   <args>
	  <arg>arg1</arg>
	  <arg>arg2</arg>
   </args>
</xgetopts>

From within a script:

xgetopts "p:,o:,d:+" $* >{args}
echo $args
phase=<[ $args/xgetopts/options/option[@name='p']/value/text()]> 
echo Phase is ${phase}

shows as 

<xgetopts>
   <options>
	  <option name="p">
		 <value>phase1</value>
	  </option>
	  <option name="o">
		 <value>test.xml</value>
	  </option>
	  <option name="d">
		 <value>dir1</value>
		 <value>dir2</value>
	  </option>
   </options>
   <args/>
</xgetopts>
Phase is phase1

xgetopts "p:,o:,d:+" $* >{args} says that the p, o and d parameters are required and come from the command line. the output is put into the 'args' variable.

These lines extract the value of the p option and echo it to stdout.

phase=<[ $args/xgetopts/options/option[@name='p']/value/text()]> 
echo Phase is ${phase}

Argument count

From the above example, to retrieve the count of options

argcount=<[ count($args/xgetopts/options/option)]> 
echo $argcount args

Required Options

Note that there is no concept of "required" options. Its up to the application to check if options are supplied.

Passthrough Options

Using -p passthrough-options allows xgetops to parse an argument list only evalutating the passthrough-options and ignoring the main options.
This is useful in modules or scripts that implement a common set of options by another script or command but extend those options or get at the list of non-option arguments.

Example from the implementation of MarkLogic get command

_opts=$<(xgetopts -a -p "c=connect:,t=text" -ps -- "$@")
shift $?

for uri ; do
   :query $_opts -q "doc(\"$uri\")"
done

This collects all optional options used by the MarkLogic query command (-c,-t) into the _opts variable as a sequence, then sets $* to the remaining options.
The -a option causes xgetopts to exit with a return status of the first non-option arguement so the "shift $?" will discard all option arguments leaving the remaining args in $*.

The :query command is then passed any -c or -t option specified

Commands
CategoryCommands

xmlsh - XML Shell : CommandXgetopts

Revision [1422]