Question

I want to develop JSF page which can display the swap size if the operating system is Linux and what percentage is utilized. I found that this information can be read from /proc/swaps. But when I open it I get this

Filename                Type        Size    Used    Priority
/dev/sda2                               partition   2047992 0   -1

How I can get just there values – 2047992 and 0? I know how to read the content of a text file. For example:

try {
    BufferedReader in = new BufferedReader(new FileReader("infilename"));
    String str;
    while ((str = in.readLine()) != null) {
        process(str);
    }
    in.close();
} catch (IOException e) {
}

And the other more advanced question is what if I have two swaps?

Regards

Answer 1

If you decide to parse the file, here is one implementation…

Pattern pattern = Pattern.compile("([\\/A-Za-z0-9]+)[\\s]+([a-z]+)[\\s]+([0-9]+)[\\s]+([0-9]+)[\\s]+([\\-0-9]+).*");
BufferedReader reader = new BufferedReader(new FileReader("/proc/swaps"));
String s = reader.readLine();
while (s!= null){                
    Matcher matcher = pattern.matcher(s);
    if (matcher.matches()){
        System.out.println(s);
        System.out.println(matcher.group(3));
        System.out.println(matcher.group(4));
    }
    s = reader.readLine();
}            
reader.close();