/the quick brown fox/ the quick brown fox The quick brown FOX What do you know about the quick brown fox? What do you know about THE QUICK BROWN FOX? /The quick brown fox/i the quick brown fox The quick brown FOX What do you know about the quick brown fox? What do you know about THE QUICK BROWN FOX? /abcd\t\n\r\f\a\e\071\x3b\$\\\?caxyz/ abcd\t\n\r\f\a\e9;\$\\?caxyz /a*abc?xyz+pqr{3}ab{2,}xy{4,5}pq{0,6}AB{0,}zz/ abxyzpqrrrabbxyyyypqAzz abxyzpqrrrabbxyyyypqAzz aabxyzpqrrrabbxyyyypqAzz aaabxyzpqrrrabbxyyyypqAzz aaaabxyzpqrrrabbxyyyypqAzz abcxyzpqrrrabbxyyyypqAzz aabcxyzpqrrrabbxyyyypqAzz aaabcxyzpqrrrabbxyyyypAzz aaabcxyzpqrrrabbxyyyypqAzz aaabcxyzpqrrrabbxyyyypqqAzz aaabcxyzpqrrrabbxyyyypqqqAzz aaabcxyzpqrrrabbxyyyypqqqqAzz aaabcxyzpqrrrabbxyyyypqqqqqAzz aaabcxyzpqrrrabbxyyyypqqqqqqAzz aaaabcxyzpqrrrabbxyyyypqAzz abxyzzpqrrrabbxyyyypqAzz aabxyzzzpqrrrabbxyyyypqAzz aaabxyzzzzpqrrrabbxyyyypqAzz aaaabxyzzzzpqrrrabbxyyyypqAzz abcxyzzpqrrrabbxyyyypqAzz aabcxyzzzpqrrrabbxyyyypqAzz aaabcxyzzzzpqrrrabbxyyyypqAzz aaaabcxyzzzzpqrrrabbxyyyypqAzz aaaabcxyzzzzpqrrrabbbxyyyypqAzz aaaabcxyzzzzpqrrrabbbxyyyyypqAzz aaabcxyzpqrrrabbxyyyypABzz aaabcxyzpqrrrabbxyyyypABBzz >>>aaabxyzpqrrrabbxyyyypqAzz >aaaabxyzpqrrrabbxyyyypqAzz >>>>abcxyzpqrrrabbxyyyypqAzz abxyzpqrrabbxyyyypqAzz abxyzpqrrrrabbxyyyypqAzz abxyzpqrrrabxyyyypqAzz aaaabcxyzzzzpqrrrabbbxyyyyyypqAzz aaaabcxyzzzzpqrrrabbbxyyypqAzz aaabcxyzpqrrrabbxyyyypqqqqqqqAzz /^(abc){1,2}zz/ abczz abcabczz zz abcabcabczz >>abczz /^(b+?|a){1,2}?c/ bc bbc bbbc bac bbac aac abbbbbbbbbbbc bbbbbbbbbbbac aaac abbbbbbbbbbbac /^(b+|a){1,2}c/ bc bbc bbbc bac bbac aac abbbbbbbbbbbc bbbbbbbbbbbac aaac abbbbbbbbbbbac /^(b+|a){1,2}?bc/ bbc /^(b*|ba){1,2}?bc/ babc bbabc bababc bababbc babababc /^(ba|b*){1,2}?bc/ babc bbabc bababc bababbc babababc /^\ca\cA\c[\c{\c:/ \x01\x01\e;z /^[ab\]cde]/ athing bthing ]thing cthing dthing ething fthing [thing \\thing /^[]cde]/ ]thing cthing dthing ething athing fthing /^[^ab\]cde]/ fthing [thing \\thing athing bthing ]thing cthing dthing ething /^[^]cde]/ athing fthing ]thing cthing dthing ething /^\/ /^/ /^[0-9]+$/ 0 1 2 3 4 5 6 7 8 9 10 100 abc /^.*nter/ enter inter uponter /^xxx[0-9]+$/ xxx0 xxx1234 xxx /^.+[0-9][0-9][0-9]$/ x123 xx123 123456 123 x1234 /^.+?[0-9][0-9][0-9]$/ x123 xx123 123456 123 x1234 /^([^!]+)!(.+)=apquxz\.ixr\.zzz\.ac\.uk$/ abc!pqr=apquxz.ixr.zzz.ac.uk !pqr=apquxz.ixr.zzz.ac.uk abc!=apquxz.ixr.zzz.ac.uk abc!pqr=apquxz:ixr.zzz.ac.uk abc!pqr=apquxz.ixr.zzz.ac.ukk /:/ Well, we need a colon: somewhere Fail if we don't /([\da-f:]+)$/i 0abc abc fed E :: 5f03:12C0::932e fed def Any old stuff 0zzz gzzz fed\x20 Any old rubbish /^.*\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/ .1.2.3 A.12.123.0 .1.2.3333 1.2.3 1234.2.3 /^(\d+)\s+IN\s+SOA\s+(\S+)\s+(\S+)\s*\(\s*$/ 1 IN SOA non-sp1 non-sp2( 1 IN SOA non-sp1 non-sp2 ( 1IN SOA non-sp1 non-sp2( /^[a-zA-Z\d][a-zA-Z\d\-]*(\.[a-zA-Z\d][a-zA-z\d\-]*)*\.$/ a. Z. 2. ab-c.pq-r. sxk.zzz.ac.uk. x-.y-. -abc.peq. /^\*\.[a-z]([a-z\-\d]*[a-z\d]+)?(\.[a-z]([a-z\-\d]*[a-z\d]+)?)*$/ *.a *.b0-a *.c3-b.c *.c-a.b-c *.0 *.a- *.a-b.c- *.c-a.0-c /^(?=ab(de))(abd)(e)/ abde /^(?!(ab)de|x)(abd)(f)/ abdf /^(?=(ab(cd)))(ab)/ abcd /^[\da-f](\.[\da-f])*$/i a.b.c.d A.B.C.D a.b.c.1.2.3.C /^\".*\"\s*(;.*)?$/ \"1234\" \"abcd\" ; \"\" ; rhubarb \"1234\" : things /^$/ \ / ^ a (?# begins with a) b\sc (?# then b c) $ (?# then end)/x ab c abc ab cde /(?x) ^ a (?# begins with a) b\sc (?# then b c) $ (?# then end)/ ab c abc ab cde /^ a\ b[c ]d $/x a bcd a b d abcd ab d /^(a(b(c)))(d(e(f)))(h(i(j)))(k(l(m)))$/ abcdefhijklm /^(?:a(b(c)))(?:d(e(f)))(?:h(i(j)))(?:k(l(m)))$/ abcdefhijklm /^[\w][\W][\s][\S][\d][\D][\b][\n][\c]][\022]/ a+ Z0+\x08\n\x1d\x12 /^[.^$|()*+?{,}]+/ .^\$(*+)|{?,?} /^a*\w/ z az aaaz a aa aaaa a+ aa+ /^a*?\w/ z az aaaz a aa aaaa a+ aa+ /^a+\w/ az aaaz aa aaaa aa+ /^a+?\w/ az aaaz aa aaaa aa+ /^\d{8}\w{2,}/ 1234567890 12345678ab 12345678__ 1234567 /^[aeiou\d]{4,5}$/ uoie 1234 12345 aaaaa 123456 /^[aeiou\d]{4,5}?/ uoie 1234 12345 aaaaa 123456 /\A(abc|def)=(\1){2,3}\Z/ abc=abcabc def=defdefdef abc=defdef /^(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)\11*(\3\4)\1(?#)2$/ abcdefghijkcda2 abcdefghijkkkkcda2 /(cat(a(ract|tonic)|erpillar)) \1()2(3)/ cataract cataract23 catatonic catatonic23 caterpillar caterpillar23 /^From +([^ ]+) +[a-zA-Z][a-zA-Z][a-zA-Z] +[a-zA-Z][a-zA-Z][a-zA-Z] +[0-9]?[0-9] +[0-9][0-9]:[0-9][0-9]/ From abcd Mon Sep 01 12:33:02 1997 /^From\s+\S+\s+([a-zA-Z]{3}\s+){2}\d{1,2}\s+\d\d:\d\d/ From abcd Mon Sep 01 12:33:02 1997 From abcd Mon Sep 1 12:33:02 1997 From abcd Sep 01 12:33:02 1997 /^12.34/s 12\n34 12\r34 /\w+(?=\t)/ the quick brown\t fox /foo(?!bar)(.*)/ foobar is foolish see? /(?:(?!foo)...|^.{0,2})bar(.*)/ foobar crowbar etc barrel 2barrel A barrel /^(\D*)(?=\d)(?!123)/ abc456 abc123 /^1234(?# test newlines inside)/ 1234 /^1234 #comment in extended re /x 1234 /#rhubarb abcd/x abcd /^abcd#rhubarb/x abcd /^(a)\1{2,3}(.)/ aaab aaaab aaaaab aaaaaab /(?!^)abc/ the abc abc /(?=^)abc/ abc the abc /^[ab]{1,3}(ab*|b)/ aabbbbb /^[ab]{1,3}?(ab*|b)/ aabbbbb /^[ab]{1,3}?(ab*?|b)/ aabbbbb /^[ab]{1,3}(ab*?|b)/ aabbbbb / (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* # optional leading comment (?: (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote ) # initial word (?: (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote ) )* # further okay, if led by a period (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* @ (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # initial subdomain (?: # (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. # if led by a period... (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # ...further okay )* # address | # or (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote ) # one word, optionally followed by.... (?: [^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037] | # atom and space parts, or... \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) | # comments, or... " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote # quoted strings )* < (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* # leading < (?: @ (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # initial subdomain (?: # (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. # if led by a period... (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # ...further okay )* (?: (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* , (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* @ (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # initial subdomain (?: # (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. # if led by a period... (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # ...further okay )* )* # further okay, if led by comma : # closing colon (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* )? # optional route (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote ) # initial word (?: (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | " (?: # opening quote... [^\\\x80-\xff\n\015"] # Anything except backslash and quote | # or \\ [^\x80-\xff] # Escaped something (something != CR) )* " # closing quote ) )* # further okay, if led by a period (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* @ (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # initial subdomain (?: # (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* \. # if led by a period... (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) # ...further okay )* # address spec (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* > # trailing > # name and address ) (?: [\040\t] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] | \( (?: [^\\\x80-\xff\n\015()] | \\ [^\x80-\xff] )* \) )* \) )* # optional trailing comment /x Alan Other user\@dom.ain \"A. Other\" (a comment) A. Other (a comment) \"/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/\"\@x400-re.lay A missing angle @,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom # Atom | # or " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " # Quoted string ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom # Atom | # or " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " # Quoted string ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # additional words )* @ [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments )* # address | # or (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom # Atom | # or " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " # Quoted string ) # leading word [^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037] * # "normal" atoms and or spaces (?: (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) | " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " ) # "special" comment or quoted string [^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037] * # more "normal" )* < [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # < (?: @ [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments )* (?: , [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. @ [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments )* )* # additional domains : [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments )? # optional route (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom # Atom | # or " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " # Quoted string ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom # Atom | # or " # " [^\\\x80-\xff\n\015"] * # normal (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015"] * )* # ( special normal* )* " # " # Quoted string ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # additional words )* @ [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments (?: \. [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. (?: [^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+ # some number of atom characters... (?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom | \[ # [ (?: [^\\\x80-\xff\n\015\[\]] | \\ [^\x80-\xff] )* # stuff \] # ] ) [\040\t]* # Nab whitespace. (?: \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: # ( (?: \\ [^\x80-\xff] | \( # ( [^\\\x80-\xff\n\015()] * # normal* (?: \\ [^\x80-\xff] [^\\\x80-\xff\n\015()] * )* # (special normal*)* \) # ) ) # special [^\\\x80-\xff\n\015()] * # normal* )* # )* \) # ) [\040\t]* )* # If comment found, allow more spaces. # optional trailing comments )* # address spec > # > # name and address ) /x Alan Other user\@dom.ain \"A. Other\" (a comment) A. Other (a comment) \"/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/\"\@x400-re.lay A missing angle ]{0,})>]{0,})>([\d]{0,}\.)(.*)((
([\w\W\s\d][^<>]{0,})|[\s]{0,}))<\/a><\/TD>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><\/TR>/is 43.Word Processor
(N-1286)Lega lstaff.comCA - Statewide /a[^a]b/ acb a\nb /a.b/ acb a\nb /a[^a]b/s acb a\nb /a.b/s acb a\nb /^(b+?|a){1,2}?c/ bac bbac bbbac bbbbac bbbbbac /^(b+|a){1,2}?c/ bac bbac bbbac bbbbac bbbbbac /(?!\A)x/m x\nb\n a\bx\n /\x0{ab}/ \0{ab} /(A|B)*?CD/ CD /(A|B)*CD/ CD /(AB)*?\1/ ABABAB /(AB)*\1/ ABABAB /(/ doesn't matter /(x)\2/ doesn't matter /((a{0,5}){0,5}){0,5}[c]/ aaaaaaaaaac aaaaaaaaaa /((a{0,5}){0,5})*[c]/ aaaaaaaaaac aaaaaaaaaa /(\b)*a/ a /(a)*b/ ab /(a|)*b/ ab b x /^(?:(a)|(b))*\1\2$/ abab /abc[^x]def/ abcxabcydef /^(a|\1x)*$/ aax aaxa // @{['']} /^(?:(a)|(b))*$/ ab /[\0]/ a \0 /[\1]/ a \1 /\10()()()()()()()()()/ doesn't matter /\10()()()()()()()()()()/ a /a(?<)b/ ab /[]/ doesn't matter /[\]/ doesn't matter /()/ a /[\x]/ x \0 /((a)*)*/ a /()a\1/ a /a\1()/ a /a(?i)a(?-i)a/ aaa aAa aAA /a(?i)a(?-i)a(?i)a(?-i)a/ aaaaa aAaAa AaAaA aAAAa AaaaA AAAAA aaAAA AAaaa /\x/ a X \0 /[a-c-e]/ a b d - /[b-\d]/ b c d - 1 /[\d-f]/ d e f - 1 /[/ doesn't matter /]/ ] a /[]/ doesn't matter /[-a-c]/ - a b d /[a-c-]/ - a b d /[-]/ a - /[--]/ a - /[---]/ a - /[--b]/ - a c /[b--]/ doesn't matter /a{/ a{ /a{}/ a{} /a{3/ a{3 /a{3,/ a{3, /a{3, 3}/ a{3,3} a{3, 3} aaa /a{3, 3}/x a{3,3} a{3, 3} aaa /a{3, }/ a{3,} a{3, } aaa /a{3, }/x a{3,} a{3, } aaa /\x x/ \0 x \0x /\x x/x \0 x \0x /\x 3/ \0003 \000 3 x3 x 3 /\x 3/x \0003 \000 3 x3 x 3 /^a{ 1}$/ a a{ 1} a{1} /^a{ 1}$/x a a{ 1} a{1} /{}/ {} a /{1}/ doesn't matter /*/ doesn't matter /|/ x /\0000/ \0000 /a(?<)b/ ab /a(?i)b/ ab aB Ab /a(?i=a)/ doesn't matter /a(?<=a){3000}a/ aa xa ax /a(?!=a){3000}a/ aa ax xa /a(){3000}a/ aa ax xa /a(?:){3000}a/ aa ax /a(?<=a)*a/ aa ax xa /a(?!=a)*a/ aa ax xa /a()*a/ aa ax xa /a(?:)*a/ aa ax xa /x(?<=a)*a/ aa xa ax /a(?<=(a))*\1/ aa /a(?<=(a))*?\1/ aa /(?=(a)\1)*aa/ aa /^((a|b){2,5}){2}$/ aaaaabbbbb /^(b*|ba){1,2}bc/ babc bbabc bababc bababbc babababc /^a{4,5}(?:c|a)c$/ aaaaac aaaaaac /^(a|){4,5}(?:c|a)c$/ aaaaac aaaaaac /(?m:^).abc$/ eeexabc eee\nxabc /(?m:^)abc/ abc \nabc /^abc/ abc \nabc /\Aabc/ abc \nabc /(?.*/)foo" /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/it/you/see/ "(?>.*/)foo" /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo /(?>(\.\d\d[1-9]?))\d+/ 1.230003938 1.875000282 1.235 /^((?>\w+)|(?>\s+))*$/ now is the time for all good men to come to the aid of the party this is not a line with only words and spaces! /(\d+)(\w)/ 12345a 12345+ /((?>\d+))(\w)/ 12345a 12345+ /(?>a+)b/ aaab /((?>a+)b)/ aaab /(?>(a+))b/ aaab /(?>b)+/ aaabbbccc /(?>a+|b+|c+)*c/ aaabbbbccccd /((?>[^()]+)|\([^()]*\))+/ ((abc(ade)ufh()()x /\(((?>[^()]+)|\([^()]+\))+\)/ (abc) (abc(def)xyz) ((()aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa /a(?-i)b/i ab Ab aB AB /(a (?x)b c)d e/ a bcd e a b cd e abcd e a bcde /(a b(?x)c d (?-x)e f)/ a bcde f abcdef /(a(?i)b)c/ abc aBc abC aBC Abc ABc ABC AbC /a(?i:b)c/ abc aBc ABC abC aBC /a(?i:b)*c/ aBc aBBc aBC aBBC /a(?=b(?i)c)\w\wd/ abcd abCd aBCd abcD /(?s-i:more.*than).*million/i more than million more than MILLION more \n than Million MORE THAN MILLION more \n than \n million /(?:(?s-i)more.*than).*million/i more than million more than MILLION more \n than Million MORE THAN MILLION more \n than \n million /(?>a(?i)b+)+c/ abc aBbc aBBc Abc abAb abbC /(?=a(?i)b)\w\wc/ abc aBc Ab abC aBC /(?<=a(?i)b)(\w\w)c/ abxxc aBxxc Abxxc ABxxc abxxC /(?:(a)|b)(?(1)A|B)/ aA bB aB bA /^(a)?(?(1)a|b)+$/ aa b bb ab /^(?(?=abc)\w{3}:|\d\d)$/ abc: 12 123 xyz /^(?(?!abc)\d\d|\w{3}:)$/ abc: 12 123 xyz /(?(?<=foo)bar|cat)/ foobar cat fcat focat foocat /(?(?a*)*/ a aa aaaa /(abc|)+/ abc abcabc abcabcabc xyz /([a]*)*/ a aaaaa /([ab]*)*/ a b ababab aaaabcde bbbb /([^a]*)*/ b bbbb aaa /([^ab]*)*/ cccc abab /([a]*?)*/ a aaaa /([ab]*?)*/ a b abab baba /([^a]*?)*/ b bbbb aaa /([^ab]*?)*/ c cccc baba /(?>a*)*/ a aaabcde /((?>a*))*/ aaaaa aabbaa /((?>a*?))*/ aaaaa aabbaa /(?(?=[^a-z]+[a-z]) \d{2}-[a-z]{3}-\d{2} | \d{2}-\d{2}-\d{2} ) /x 12-sep-98 12-09-98 sep-12-98 /(?<=(foo))bar\1/ foobarfoo foobarfootling foobar barfoo /(?i:saturday|sunday)/ saturday sunday Saturday Sunday SATURDAY SUNDAY SunDay /(a(?i)bc|BB)x/ abcx aBCx bbx BBx abcX aBCX bbX BBX /^([ab](?i)[cd]|[ef])/ ac aC bD elephant Europe frog France Africa /^(ab|a(?i)[b-c](?m-i)d|x(?i)y|z)/ ab aBd xy xY zebra Zambesi aCD XY /(?<=foo\n)^bar/m foo\nbar bar baz\nbar /(?<=(?]&/ <&OUT /^(a\1?){4}$/ aaaaaaaaaa AB aaaaaaaaa aaaaaaaaaaa /^(a(?(1)\1)){4}$/ aaaaaaaaaa aaaaaaaaa aaaaaaaaaaa /(?:(f)(o)(o)|(b)(a)(r))*/ foobar /(?<=a)b/ ab cb b /(?a+)ab/ /(?>a+)b/ aaab /([[:]+)/ a:[b]: /([[=]+)/ a=[b]= /([[.]+)/ a.[b]. /((?>a+)b)/ aaab /(?>(a+))b/ aaab /((?>[^()]+)|\([^()]*\))+/ ((abc(ade)ufh()()x /a\Z/ aaab a\nb\n /b\Z/ a\nb\n /b\z/ /b\Z/ a\nb /b\z/ a\nb /^(?>(?(1)\.|())[^\W_](?>[a-z0-9-]*[^\W_])?)+$/ a abc a-b 0-9 a.b 5.6.7 the.quick.brown.fox a100.b200.300c 12-ab.1245 \ .a -a a- a. a_b a.- a.. ab..bc the.quick.brown.fox- the.quick.brown.fox. the.quick.brown.fox_ the.quick.brown.fox+ /(?>.*)(?<=(abcd|wxyz))/ alphabetabcd endingwxyz a rather long string that doesn't end with one of them /word (?>(?:(?!otherword)[a-zA-Z0-9]+ ){0,30})otherword/ word cat dog elephant mussel cow horse canary baboon snake shark otherword word cat dog elephant mussel cow horse canary baboon snake shark /word (?>[a-zA-Z0-9]+ ){0,30}otherword/ word cat dog elephant mussel cow horse canary baboon snake shark the quick brown fox and the lazy dog and several other words getting close to thirty by now I hope /(?<=\d{3}(?!999))foo/ 999foo 123999foo 123abcfoo /(?<=(?!...999)\d{3})foo/ 999foo 123999foo 123abcfoo /(?<=\d{3}(?!999)...)foo/ 123abcfoo 123456foo 123999foo /(?<=\d{3}...)(?\s*)=(?>\s*) # find Z)+|A)*/ ZABCDEFG /((?>)+|A)*/ ZABCDEFG /a*/g abbab /^[a-\d]/ abcde -things 0digit bcdef /^[\d-a]/ abcde -things 0digit bcdef