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53  *
54  * Portions of this software are based upon software originally written
55  * by Daniel F. Savarese. We appreciate his contributions.
56  */

57
58 import java.io.*;
59 import java.util.*;
60
61 import org.apache.oro.text.*;
62 import org.apache.oro.text.regex.*;
63
64 /**
65  * This is a sample program mimicking the Unix groups command. It assumes
66  * the /etc/group file exists.
67  *
68  @author <a HREF="dfs@savarese.org">Daniel F. Savarese</a>
69  @version $Id: groups.java,v 1.1.1.1 2000/07/23 23:08:48 jon Exp $
70  */

71 public final class groups {
72
73   public static final void main(String JavaDoc[] args) {
74     int user;
75     MatchActionProcessor processor = new MatchActionProcessor();
76     final Hashtable groups = new Hashtable();
77     Vector users = new Vector();
78     Enumeration usersElements;
79     MatchAction action = new MatchAction() {
80       public void processMatch(MatchActionInfo info) {
81     // Add group name to hashtable entry
82
((Vector)groups.get(info.match.toString())).addElement(
83                        info.fields.elementAt(0));
84       }
85     };
86
87     if(args.length == 0) {
88       // No arguments assumes calling user
89
args = new String JavaDoc[1];
90       args[0] = System.getProperty("user.name");
91     }
92
93     try {
94       processor.setFieldSeparator(":");
95       for(user = 0; user < args.length; user++) {
96     // Screen out duplicates
97
if(!groups.containsKey(args[user])) {
98       groups.put(args[user], new Vector());
99       // We assume usernames contain no special characters
100
processor.addAction(args[user], action);
101       // Add username to Vector to preserve argument order when printing
102
users.addElement(args[user]);
103     }
104       }
105     } catch(MalformedPatternException e) {
106       e.printStackTrace();
107       System.exit(1);
108     }
109
110     try {
111       processor.processMatches(new FileInputStream("/etc/group"),
112                    System.out);
113     } catch(IOException e) {
114       e.printStackTrace();
115       System.exit(1);
116     }
117
118     usersElements = users.elements();
119
120     while(usersElements.hasMoreElements()) {
121       String JavaDoc username;
122       Enumeration values;
123
124       username = (String JavaDoc)usersElements.nextElement();
125       values = ((Vector)groups.get(username)).elements();
126
127       System.out.print(username + " :");
128       while(values.hasMoreElements()) {
129     System.out.print(" " + values.nextElement());
130       }
131       System.out.println();
132     }
133
134     System.out.flush();
135   }
136
137 }
138
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