Java tutorial
import java.io.Console; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; public class Main { public static void main(String[] args) { Pattern pattern = null; Matcher matcher = null; Console console = System.console(); while (true) { try { pattern = Pattern.compile(console.readLine("%nEnter your regex: ")); matcher = pattern.matcher(console.readLine("Enter input string to search: ")); } catch (PatternSyntaxException pse) { console.format("There is a problem with the regular expression!%n"); console.format("The pattern in question is: %s%n", pse.getPattern()); console.format("The description is: %s%n", pse.getDescription()); console.format("The message is: %s%n", pse.getMessage()); console.format("The index is: %s%n", pse.getIndex()); System.exit(0); } boolean found = false; while (matcher.find()) { console.format("I found the text \"%s\" starting at " + "index %d and ending at index %d.%n", matcher.group(), matcher.start(), matcher.end()); found = true; } if (!found) { console.format("No match found.%n"); } } } }