Labels:bulletin board | chat room | reckoner | sky OCR: Regular Expressions The question mark works similar to and + but it searches for zero or one occurence of the preceding pattern. For example, ab?c will find the strings "ac" and abc" and nothing else The verti ical bar (|) is OR operator. It searches for occurences of eit For examp le, the expression abc xyz will find the stri ings "abc" and "xyz" and nothing else. Unlike the s opera tor applies not just to the si ingl e characters around but C C ever and end of the regul .ar expression If you want to constrain to sub-p regex, you must use brackets; for i|ra)g will find the strings "dig" and "drag and constrain search t o the begi .nni ing and end of line, respective Xvz will find the string "xyz" only if it's at the beginning of line, and xyz$ will find the string "xyz" only if it's at th ...
