Testing Perl-Compatible Regular Expressions
PCRE version 1.07 16-Feb-1998

/(a)b|/
Identifying subpattern count = 1
No options
No first char

/(a*)*/
Failed: operand of unlimited repeat could match the empty string at offset 4

/(abc|)+/
Failed: operand of unlimited repeat could match the empty string at offset 6

/abc/
Identifying subpattern count = 0
No options
First char = 'a'
    abc
 0: abc
    defabc
 0: abc
    \Aabc
 0: abc
    \IABC
 0: ABC
    *** Failers
No match
    \Adefabc
No match
    ABC
No match

/^abc/
Identifying subpattern count = 0
Options: anchored
No first char
    abc
 0: abc
    \Aabc
 0: abc
    *** Failers
No match
    defabc
No match
    \Adefabc
No match

/a+bc/
Identifying subpattern count = 0
No options
First char = 'a'

/a*bc/
Identifying subpattern count = 0
No options
No first char

/a{3}bc/
Identifying subpattern count = 0
No options
First char = 'a'

/(abc|a+z)/
Identifying subpattern count = 1
No options
First char = 'a'

/^abc$/
Identifying subpattern count = 0
Options: anchored
No first char
    abc
 0: abc
    \Mdef\nabc
 0: abc
    *** Failers
No match
    def\nabc
No match

/abc\/
Failed: \ at end of pattern at offset 4

/ab\gdef/X
Failed: unrecognized character follows \ at offset 3

/x{5,4}/
Failed: numbers out of order in {} quantifier at offset 5

/z{65536}/
Failed: number too big in {} quantifier at offset 7

/[abcd/
Failed: missing terminating ] for character class at offset 5

/[\B]/
Failed: invalid escape sequence in character class at offset 2

/[a-\w]/
Failed: invalid escape sequence in character class at offset 4

/[z-a]/
Failed: range out of order in character class at offset 3

/^*/
Failed: nothing to repeat at offset 1

/(abc/
Failed: missing ) at offset 4

/(?# abc/
Failed: missing ) after comment at offset 7

/(?z)abc/
Failed: unrecognized character after (? at offset 2

/.*b/
Identifying subpattern count = 0
Options: anchored
No first char

/.*?b/
Identifying subpattern count = 0
Options: anchored
No first char

/cat|dog|elephant/
Identifying subpattern count = 0
No options
No first char
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/S
Identifying subpattern count = 0
No options
No first char
Starting character set: c d e 
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/iS
Identifying subpattern count = 0
Options: caseless
No first char
Starting character set: C D E c d e 
    this sentence eventually mentions a CAT cat
 0: CAT
    this sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/cat|dog|elephant/IS
Identifying subpattern count = 0
No options
No first char
Starting character set: C D E c d e 
    this sentence eventually mentions a CAT cat
 0: cat
    this sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/cat|dog|elephant/IS
Identifying subpattern count = 0
No options
No first char
Starting character set: C D E c d e 
    \Ithis sentence eventually mentions a CAT cat
 0: CAT
    \Ithis sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/a|[bcd]/S
Identifying subpattern count = 0
No options
No first char
Starting character set: a b c d 

/(a|[^\dZ])/S
Identifying subpattern count = 1
No options
No first char
Starting character set: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( ) * + , - . / : ; < = > 
  ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y [ \ ] ^ _ ` a b c d 
  e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 
  \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 
  \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 
  \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 
  \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf 
  \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce 
  \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd 
  \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec 
  \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb 
  \xfc \xfd \xfe \xff 

/(a|b)*[\s]/S
Identifying subpattern count = 1
No options
No first char
Starting character set: \x09 \x0a \x0b \x0c \x0d \x20 a b 

/(ab\2)/
Failed: back reference to non-existent subpattern at offset 4

/{4,5}abc/
Failed: nothing to repeat at offset 4

/(a)(b)(c)\2/
Identifying subpattern count = 3
No options
First char = 'a'
    abcb
 0: abcb
 1: a
 2: b
 3: c
    \O0abcb
Matched, but too many substrings
    \O2abcb
Matched, but too many substrings
 0: abcb
    \O4abcb
Matched, but too many substrings
 0: abcb
 1: a
    \O6abcb
Matched, but too many substrings
 0: abcb
 1: a
 2: b
    \O8abcb
 0: abcb
 1: a
 2: b
 3: c

/(a)bc|(a)(b)\2/
Identifying subpattern count = 3
No options
First char = 'a'
    abc
 0: abc
 1: a
    \O0abc
Matched, but too many substrings
    \O2abc
Matched, but too many substrings
 0: abc
    \O4abc
 0: abc
 1: a
    aba
 0: aba
 1: <unset>
 2: a
 3: b
    \O0aba
Matched, but too many substrings
    \O2aba
Matched, but too many substrings
 0: aba
    \O4aba
Matched, but too many substrings
 0: aba
 1: <unset>
    \O6aba
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    \O8aba
 0: aba
 1: <unset>
 2: a
 3: b

/^a.b/
Identifying subpattern count = 0
Options: anchored
No first char
    \Sa\nb
 0: a\x0ab

/abc$/E
Identifying subpattern count = 0
Options: dollar_endonly
First char = 'a'
    abc
 0: abc
    *** Failers
No match
    abc\n
No match
    abc\ndef
No match

/abc$/
Identifying subpattern count = 0
No options
First char = 'a'
    *** Failers
No match
    \Eabc\n
No match
    \Eabc\ndef
No match

/abc$/m
Identifying subpattern count = 0
Options: multiline
First char = 'a'
    \Eabc\n
 0: abc
    \Eabc\ndef
 0: abc

/(a)(b)(c)(d)(e)\6/
Failed: back reference to non-existent subpattern at offset 16

/the quick brown fox/
Identifying subpattern count = 0
No options
First char = 't'
    the quick brown fox
 0: the quick brown fox
    this is a line with the quick brown fox
 0: the quick brown fox

/the quick brown fox/A
Identifying subpattern count = 0
Options: anchored
No first char
    the quick brown fox
 0: the quick brown fox
    *** Failers
No match
    this is a line with the quick brown fox
No match

/ab(?z)cd/
Failed: unrecognized character after (? at offset 4

".*/\Xfoo"X
Identifying subpattern count = 0
Options: anchored extra
No first char
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/it/you/see/
No match

".*/\Xfoo"X
Identifying subpattern count = 0
Options: anchored extra
No first char
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo
 0: /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo

/(\.\d\d[1-9]?)\d+/
Identifying subpattern count = 1
No options
First char = '.'
    1.230003938
 0: .230003938
 1: .23
    1.875000282
 0: .875000282
 1: .875
    1.235 
 0: .235
 1: .23

/(\.\d\d[1-9]?)\X\d+/X
Identifying subpattern count = 1
Options: extra
First char = '.'
    1.230003938
 0: .230003938
 1: .23
    1.875000282
 0: .875000282
 1: .875
    *** Failers 
No match
    1.235 
No match

/(\.\d\d((?=0)|\d(?=\d)))/
Identifying subpattern count = 2
No options
First char = '.'
    1.230003938
 0: .23
 1: .23
 2: 
    1.875000282
 0: .875
 1: .875
 2: 5
    *** Failers 
No match
    1.235 
No match

/^(\w+\X|\s+\X)*$/X
Identifying subpattern count = 1
Options: anchored extra
No first char
    now is the time for all good men to come to the aid of the party
 0: now is the time for all good men to come to the aid of the party
 1: party
    *** Failers
No match
    this is not a line with only words and spaces!
No match
    
/^abc|def/
Identifying subpattern count = 0
No options
No first char
    abcdef
 0: abc
    abcdef\B
 0: def

/.*((abc)$|(def))/
Identifying subpattern count = 3
Options: anchored
No first char
    defabc
 0: defabc
 1: abc
 2: abc
    \Zdefabc
 0: def
 1: def
 2: <unset>
 3: def

/abc/P
    abc
 0: abc
    *** Failers
No match: POSIX code 17: match failed
    
/^abc|def/P
    abcdef
 0: abc
    abcdef\B
 0: def

/.*((abc)$|(def))/P
    defabc
 0: defabc
 1: abc
 2: abc
    \Zdefabc
 0: def
 1: def
 3: def
  
/the quick brown fox/P
    the quick brown fox
 0: the quick brown fox
    *** Failers 
No match: POSIX code 17: match failed
    The Quick Brown Fox 
No match: POSIX code 17: match failed

/the quick brown fox/Pi
    the quick brown fox
 0: the quick brown fox
    The Quick Brown Fox 
 0: The Quick Brown Fox

/abc.def/P
    *** Failers
No match: POSIX code 17: match failed
    abc\ndef
No match: POSIX code 17: match failed
    
/abc$/P
    abc
 0: abc
    abc\n 
 0: abc

/abc\/P
Failed: POSIX code 9: bad escape sequence at offset 4     

/(abc)\2/P
Failed: POSIX code 15: bad back reference at offset 6     

/(abc\1)/P
    abc
No match: POSIX code 15: bad back reference

"(?>.*/)foo"X
Identifying subpattern count = 0
Options: anchored extra
No first char
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/it/you/see/
No match

"(?>.*/)foo"X
Identifying subpattern count = 0
Options: anchored extra
No first char
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo
 0: /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo

/(?>(\.\d\d[1-9]?))\d+/X
Identifying subpattern count = 1
Options: extra
No first char
    1.230003938
 0: .230003938
 1: .23
    1.875000282
 0: .875000282
 1: .875
    *** Failers 
No match
    1.235 
No match

/^((?>\w+)|(?>\s+))*$/X
Identifying subpattern count = 1
Options: anchored extra
No first char
    now is the time for all good men to come to the aid of the party
 0: now is the time for all good men to come to the aid of the party
 1: party
    *** Failers
No match
    this is not a line with only words and spaces!
No match
    
/(\d+)(\w)/X
Identifying subpattern count = 2
Options: extra
No first char
    12345a
 0: 12345a
 1: 12345
 2: a
    12345+ 
 0: 12345
 1: 1234
 2: 5

/((?>\d+))(\w)/X
Identifying subpattern count = 2
Options: extra
No first char
    12345a
 0: 12345a
 1: 12345
 2: a
    *** Failers
No match
    12345+ 
No match

/([a]*)*/
Failed: operand of unlimited repeat could match the empty string at offset 6

/([ab]*)*/
Failed: operand of unlimited repeat could match the empty string at offset 7

/([^a]*)*/
Failed: operand of unlimited repeat could match the empty string at offset 7

/([^ab]*)*/
Failed: operand of unlimited repeat could match the empty string at offset 8

/([a]*?)*/
Failed: operand of unlimited repeat could match the empty string at offset 7

/([ab]*?)*/
Failed: operand of unlimited repeat could match the empty string at offset 8

/([^a]*?)*/
Failed: operand of unlimited repeat could match the empty string at offset 8

/([^ab]*?)*/
Failed: operand of unlimited repeat could match the empty string at offset 9

/(?>a*)*/X
Failed: nothing to repeat at offset 6

/((?>a*))*/X
Failed: operand of unlimited repeat could match the empty string at offset 8

/((?>a*?))*/X
Failed: operand of unlimited repeat could match the empty string at offset 9

/)/
Failed: unmatched brackets at offset 0

/a[]b/
Failed: missing terminating ] for character class at offset 4

/[^a]/
Identifying subpattern count = 0
No options
No first char
    \Iaaaabcd
 0: b
    \IaaAabcd 
 0: b

/[^az]/
Identifying subpattern count = 0
No options
No first char
    \Iaaaabcd
 0: b
    \IaaAabcd 
 0: b

/[^az]/
Identifying subpattern count = 0
No options
No first char
    \Izazabcd
 0: b
    \IAaZabcd 
 0: b
    
/[^aeiou ]{3,}/
Identifying subpattern count = 0
No options
No first char
    co-processors, and for 
 0: -pr
    \Ico-processors, and for 
 0: -pr
    
/((a)*)*/
Failed: operand of unlimited repeat could match the empty string at offset 6

/((a|b|c)*)*/
Failed: operand of unlimited repeat could match the empty string at offset 10

/ End of test input /
Identifying subpattern count = 0
No options
First char = ' '