How to match java cmd arguments with regular expression?

Question

I have cmd like this one:

java Test -p 127.0.0.1:8080 -d D:\Desktop\temp.exe -o mingw -s 1024 -t 2000

I want to get the args with -p,-d or -s(exclude -p,-d,-s itself), and discard other args.

I tried hours but had no result,is there any one can help me?

I tried the arg[i] and arg[i+1] way,but if args like this:-p -d xxx, the user do not enter -p value, this solution will take no effect and cause problems.

Give the code you have tried. Why not give a starting point? — Marko Topolnik, Jul 30 '12 at 10:03

score 2 · Answer 1 · answered Jul 30 '12 at 10:05

2

use this regex -(\w) ([\w!@#$%^&*():\\/.]+) group[1] contain flag, group[2] contain argument

answered Jul 30 '12 at 10:05

burning_LEGION

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could you explain this regex? i can not understand – kwf2030 Jul 31 '12 at 01:09
`-` litteral symbol, `(\w)` any digit/letter/_, `([\w!@#$%^&*():\\/.])` any symbol from `[]`, `+` 1 and more previos symbols – burning_LEGION Jul 31 '12 at 08:20

score 2 · Accepted Answer · edited May 23 '17 at 12:31

If all your options are in same form -x value, then you can split your args array into groups in form of -d 127.0.0.1:8080, -d D:...

for(int i=0; i < args.length; i+=2){
    //group args
}

for each group in groups:
    if group[0].equals("-d"){
          //do something
    }
}

Or, just have a look at existing OptionParser libraries in Java. How to parse command line arguments in Java?

score 1 · Answer 3 · answered Jul 30 '12 at 10:05

1

How about...

for(int i = 0; i < args.length; i+=2) { 
 if(args[i].equals("-p") {
   //args[i+1] is the value
 } 
 ... 
}

It doesn't use regexes, yay :)

answered Jul 30 '12 at 10:05

nullpotent

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I prefer to regex, if the user entered wrong args,like -p -d xxx,the arg[i+1] goes the wrong way. – kwf2030 Jul 31 '12 at 00:53

Marko Topolnik · Answer 4 · 2012-07-31T07:16:17.633

1

This solution assembles your args into a map:

public static void main(String[] args) {
  final Map<Character, String> am = new HashMap<Character, String>();
  for (int i = 0; i+1 < args.length; i++)
    if (args[i].matches("-[pds]") && !args[i+1].startsWith("-"))
      am.put(args[i].charAt(1), args[++i]);
  System.out.println(am);
}

edited Jul 31 '12 at 07:16

answered Jul 30 '12 at 10:08

Marko Topolnik

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if the args entered wrong,like -p -d xxx,no -p value,this would be wrong – kwf2030 Jul 31 '12 at 00:59
...and very easily fixable. Fixed. – Marko Topolnik Jul 31 '12 at 07:16

score 0 · Answer 5 · answered Jul 30 '12 at 10:07

0

Try not to create one big expression but various small ones. E.g the expression to match the -p part would be: -p ?(.*?) (untested).

answered Jul 30 '12 at 10:07

Sebastian Hoffmann

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score 0 · Answer 6 · answered Jul 30 '12 at 10:14

You don't need regular expressions for this, as the arguments come in an array, so you just loop over it:

public static void main(String[] args) {
  Map<String, String> argsMap = new HashMap<String, String>();
  int i = 0;
  while(i < args.length - 1 && args[i].startsWith("-")) {
    argsMap.put(args[i].substring(1), args[++i]);
  }

  System.out.println("-p arg was " + argsMap.get("p"));
  // etc.
}

How to match java cmd arguments with regular expression?

6 Answers6