Regular Expressions :: metasymbols

• alternation (think 'or'):

    m/a|b|c/; # 'a' or 'b' or 'c'

• character classes (sets of characters, but matches only one character at a time):

    m/[aeiou]/  # matches one vowel
    m/[^aeiou]/ # ^ negates, matches consonant

• grouping into single units: m/([aeiou]foobar)/

• anchors: ^ matches the beginning of string, $ matches the end of string