Exercise: Regexes part 1
Regexes exercise 1
Pick up a file with some text in it. Write a script (one for each item) that prints out every line from the file that matches the requirement. You can use the script at the end of the page as a starting point but you will have to change it!
- has a 'q'
- starts with a 'q'
- has 'th'
- has an 'q' or a 'Q'
- has a '*' in it
- starts with an 'q' or an 'Q'
- has both 'a' and 'e' in it
- has an 'a' and somewhere later an 'e'
- does not have an 'a'
- does not have an 'a' nor 'e'
- has an 'a' but not 'e'
- has at least 2 consequtive vowels (a,e,i,o,u) like in the word "bear"
- has at least 3 vowels
- has at least 6 characters
- has at exactly 6 characters
- all the words with either 'Bar' or 'Baz' in them
- all the rows with either 'apple pie' or 'banana pie' in them
- for each row print if it was apple or banana pie?
- Bonus: Print if the same word appears twice in the same line
- Bonus: has a double character (e.g. 'oo')
Ruby
examples/ruby/regex_exercise_1.rbif ARGV.length != 1 puts "Usage: Needs filename" exit end fh = open ARGV[0] fh.each do |line| if /REGEX/.match(line) print line end end
Python
examples/python/regex_exercise_1.py#!/usr/bin/env python from __future__ import print_function import sys import re if len(sys.argv) != 2: print("Usage:", sys.argv[0], "FILE") exit() filename = sys.argv[1] f = open(filename, 'r') for line in f: print(line, end=" ") match = re.search(r'REGEX1', line) if match: print(" Matching 1", match.group(0)) match = re.search(r'REGEX2', line) if match: print(" Matching 2", match.group(0))
Perl
For Perl check out the respective regex exercise page on the Perl Maven site.
Solution - Perl 5
Published on 2015-10-30