EL246 / regex_search

regex_search

regex_search is a pattern matcher that checks whether a given string matches a given pattern.

Usage

regex_search accepts two arguments, a pattern to be matched and a string. It returns true if the pattern matches the entire string. Otherwise, it returns false.

java regex_search.Main <pattern> <string>

Where:

• <pattern> is mandatory, and is a string pattern

• <string> is mandatory, and is the string that is checked against the pattern

• <pattern> supports the following patterns and special characters:

  • A non-special character in a pattern matches only that character.
  • The special-character . in the pattern matches any single character.
  • The special-character ? in the pattern does not match any character, but indicates the following character in the pattern can match zero or one times.
  • The special-character * in the pattern does not match any character, but indicates the following character in the pattern can match zero or more times.
  • The special-character + in the pattern does not match anything, but indicates the following character in the pattern can match one or more times.

• it is assumed that a ?, *, or + will always be followed by another character

Here are some sample messages:

"ERROR: *." "ERROR: file not found" should return true. "a.c" "abc" should return true. "adc" "abc" should return false.

Possible responses are true or false.

Getting Started

To start the application, you can compile and run the source code. Run with -ea (-enableassertions) flag to enable assertions.

java -ea regex_search.Main <pattern> <string>

Running the tests

JUnit testing framework was used for this project. To run the tests simply run the PatternMatcherTest. Maven can be used for this, with the following commands:

mvn clean
mvn test