Loading...

​​Regex/Grep

• ​​A regular expression, regex or regexp (sometimes called a rational expression) is a sequence of characters that define a search pattern. Usually such patterns are used by string searching algorithms for "find" or "find and replace" operations on strings, or for input validation. It is a technique developed in theoretical computer science and formal language theory.

​​

​​Wildcards

​​You can replace parts of words with wildcards matching one, multiple, or a range of characters:

​​? Matches exactly one character.

​​*: Matches none, one, or multiple characters.

​​[a-b]: Matches one character of the range “a” through “b”.

​​[abc…] or [a|b|c|…]: Matches one character out of the given list of characters.

​​[^…]: Matches one character that is not contained in the given list or range.

​​

​​Useful Regex expressions

​​

​​Words in the latin alphabet

​​

• ​​\b[A-Za-z]+\b Words in the Latin alphabet

• ​​\b assert position at a word boundary

• ​​A-Z a single character in the range between A and Z (case sensitive)

• ​​a-z a single character in the range between a and z (case sensitive)

• ​​+ Quantifier: matches between one and unlimited times, as many times as possible, giving back as needed

• ​​\b assert position at a word boundary

​​

​​Words in greek

​​

• ​​\b\p{Greek}+ Words in greek

​​

• ​​[[:space:]][Α-ΩἉἙἩἹὉὩὙἌἜἬἼὌὬἍἝἭἽὍὭὝἊἚἪἺὊὬἋἛἫἻὋὫὛ] Words in greek beginning in uppercase after a whitespace space. Useful for identifying and isolating the beginning of new sections.

​​

​​Page numbering

​​

• ​​\d*[a|b]\d\d Bekker numbering

​​

• ​​\d*[a|b|c|d|e]\d\d Stephanus numbering

​​

​​

​​

​​