GetOptpublic class GetOpt extends Object | GetOpt is a Java equivalent to the C getopt() library function
discussed in man page getopt(3C). It provides command line
parsing for Java applications. It supports the most rules of the
command line standard (see man page intro(1)) including stacked
options such as '-sxm' (which is equivalent to -s -x -m); it
handles special '--' option that signifies the end of options.
Additionally this implementation of getopt will check for
mandatory arguments to options such as in the case of
'-d ' it will throw a MissingOptArgException if the
option argument '' is not included on the commandline.
getopt(3C) does not check for this. |
| Fields Summary |
|---|
| private Option | theCurrentOption | | private ListIterator | theOptionsIterator | | private List | theOptions | | private List | theCmdArgs | | private OptionMatcher | theOptionMatcher |
| Constructors Summary |
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public GetOpt(String[] args, String optString)
theOptions = new ArrayList();
int currOptIndex = 0;
theCmdArgs = new ArrayList();
theOptionMatcher = new OptionMatcher(optString);
// fill in the options list
for(int i=0; i<args.length; i++){
String token = args[i];
int tokenLength = token.length();
if(token.equals("--")){ // end of opts
currOptIndex = i+1; // set index of first operand
break; // end of options
}
else if(token.startsWith("-") && tokenLength == 2){
// simple option token such as '-s' found
theOptions.add(new Option(token.charAt(1)));
}
else if(token.startsWith("-") && tokenLength > 2){
// stacked options found, such as '-shm'
// iterate thru the tokens after the dash and
// add them to theOptions list
for(int j=1; j<tokenLength; j++){
theOptions.add(new Option(token.charAt(j)));
}
}
else if(!token.startsWith("-")){
// case 1- there are not options stored yet therefore
// this must be an command argument, not an option argument
if(theOptions.size() == 0){
currOptIndex = i;
break; // stop processing options
}
else {
// case 2-
// there are options stored, check to see if
// this arg belong to the last arg stored
int indexoflast=0;
indexoflast = theOptions.size()-1;
Option op = (Option)theOptions.get(indexoflast);
char opLetter = op.getArgLetter();
if(!op.hasArg() && theOptionMatcher.hasArg(opLetter)){
op.setArg(token);
}
else{
// case 3 -
// the last option stored does not take
// an argument, so again, this argument
// must be a command argument, not
// an option argument
currOptIndex = i;
break; // end of options
}
}
}// end option does not start with "-"
} // end for args loop
// attach an iterator to list of options
theOptionsIterator = theOptions.listIterator();
// options are done, now fill out cmd arg list with remaining args
for(int i=currOptIndex; i<args.length; i++){
String token = args[i];
theCmdArgs.add(token);
}
|
| Methods Summary |
|---|
| public java.lang.String[] | getCmdArgs()gets list of the commandline arguments. For example, in command
such as 'cmd -s -d file file2 file3 file4' with the usage
'cmd [-s] [-d ] ...', getCmdArgs() would return
the list {file2, file3, file4}.
String[] retval = new String[theCmdArgs.size()];
int i=0;
for(ListIterator it=theCmdArgs.listIterator(); it.hasNext();){
retval[i++] = (String)it.next();
}
return retval;
| | public int | getNextOption()gets the next option found in the commandline. Distinguishes
between two bad cases, one case is when an illegal option
is found, and then other case is when an option takes an
argument but no argument was found for that option.
If the option found was not declared in the optString, then
an IllegalArgumentException will be thrown (case 1).
If the next option found has been declared to take an argument,
and no such argument exists, then a MissingOptArgException
is thrown (case 2).
int retval = -1;
if(theOptionsIterator.hasNext()){
theCurrentOption = (Option)theOptionsIterator.next();
char c = theCurrentOption.getArgLetter();
boolean shouldHaveArg = theOptionMatcher.hasArg(c);
String arg = theCurrentOption.getArgument();
if(!theOptionMatcher.match(c)) {
ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_CMDLINE_OPTION_ERR,
new Character(c));
throw (new IllegalArgumentException(msg.toString()));
}
else if(shouldHaveArg && (arg == null)) {
ErrorMsg msg = new ErrorMsg(ErrorMsg.CMDLINE_OPT_MISSING_ARG_ERR,
new Character(c));
throw (new MissingOptArgException(msg.toString()));
}
retval = c;
}
return retval;
| | public java.lang.String | getOptionArg()gets the argument for the current parsed option. For example,
in case of '-d ', if current option parsed is 'd' then
getOptionArg() would return ''.
String retval = null;
String tmp = theCurrentOption.getArgument();
char c = theCurrentOption.getArgLetter();
if(theOptionMatcher.hasArg(c)){
retval = tmp;
}
return retval;
| | public void | printOptions()debugging routine to print out all options collected
for(ListIterator it=theOptions.listIterator(); it.hasNext();){
Option opt = (Option)it.next();
System.out.print("OPT =" + opt.getArgLetter());
String arg = opt.getArgument();
if(arg != null){
System.out.print(" " + arg);
}
System.out.println();
}
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