System Functions

Mask Character

Format in Pattern$

Search

^ (Caret)

At the start of regular expression

To find a match with the start of the string being searched

$ (Dollar Sign)

At the end of regular expression

To find a match with the end of the string being searched

. (Period)

Anywhere in the pattern except within square brackets

To find a match with any character

(string)

String of characters (or other codes) enclosed in parentheses

To define a sub-pattern to match

If 'OM'=0 and PxPlus 2014 is used, then it also sets up the sub-pattern to be captured.

[string]

String enclosed in square brackets

To find a match with any character in that string

[^string]

Square bracketing combined with a caret ^ as the first character of the string

To find a match with any character except the characters in the string

Example:

[xyz] matches x, y, or z, while [^xyz] matches a, b, c, but not x, y, or z.

[str-ing]

Dash within string in square brackets

To form expressions

Example:

[a-bd-z] to search for a match with any lowercase letter except c

* (Asterisk)

At the end of a character (or sub-pattern)

To search for zero or more occurrences of the character (or sub-pattern)

Example:

In fo*, the * operates on the o; it matches f, fo, foo, etc. but does not match fa. The expression f(at)* matches f, fat, fatat, fatatat, etc.

+ (Plus Sign)

At the end of a character (or sub-pattern)

To find a match with one or more occurrences of the character (or sub-pattern)

Example:

In fa+, matches fa, faa, faaa, etc. but not f.

{min,max}

At the end of a character (or sub-pattern)

To find a match with at least (min) and at most (max) occurrences of the character (or sub-pattern)

Example:

go{2,4}d matches good, good, or gooood.

Note:
'OM'=0 on PxPlus 2014 Only

? (Question Mark)

At the end of a character (or sub-pattern) or following a *, +, or {min,max} metacharacter

Used at the end of a character (or sub-pattern) to indicate that it is optional

Example:

colou?r matches color or colour and sea(horse)? matches sea or seahorse.

Used after a *, +, or {min,max} metacharacter to indicate that the preceding metacharacter should match the shortest match

Example:

l+? matches l but not ll in the string hello world.

Note:
'OM'=0 on PxPlus 2014 Only

| (Vertical Bar)

Separating two expressions

To find a match for either of the two expressions

Example:

cat|dog matches cat or dog.
c(at)|(dog) matches cat or dog.
my ((cat)|(dog)) matches my cat or my dog.

\ (Backslash)

Preceding a mask character

To indicate that the character that follows is to be taken literally

Example:

To search for multiple asterisks, use \**.

ASCII Character Classes

The following can be used anywhere in the pattern to match common types of characters:

Note:
This only works for 'OM'=0 on PxPlus 2014.

\a

Alarm; that is, the BEL character (Hex 07)

\cx

"control-x", where x is any ASCII character

\e

Escape (Hex 1B)

\f

Form feed (Hex 0C)

\n

Linefeed (Hex 0A)

\r

Carriage return (Hex 0D)

\t

Tab (Hex 09)

0dd

Character with octal code 0dd

\ddd

Character with octal code ddd or back reference

\o{ddd..}

Character with octal code ddd

\xhh

Character with Hex code hh

\x{hhh..}

Character with Hex code hhh (Non-JavaScript Mode)

\uhhhh

Character with Hex code hhhh (JavaScript Mode Only)

\d

Any decimal digit

\D

Any character that is not a decimal digit

\h

Any horizontal white space character

\H

Any character that is not a horizontal white space character

\s

Any white space character

\S

Any character that is not a white space character

\v

Any vertical white space character

\V

Any character that is not a vertical white space character

\w

Any "word" character

\W

Any "non-word" character

\b

Matches at a word boundary

\B

Matches when not at a word boundary

\A

Matches at the start of the subject

\Z

Matches at the end of the subject; also matches before a new line at the end of the subject

\z

Matches only at the end of the subject

\G

Matches at the first matching position in the subject

ASCII Character Classes

The following can be used as part of any string enclosed in square brackets to match common types of characters (i.e. [[:digit:]%] will match any digit or percent sign character):

Note:
This only works for 'OM'=0 on PxPlus 2014.

[:alnum:]

Alphanumeric characters

[:alpha:]

Alphabetic characters

[:ascii:]

ASCII characters

[:blank:]

Space and tab

[:cntrl:]

Control characters

[:digit:]

Digits

[:graph:]

Visible characters (i.e. Anything except spaces, control characters, etc.)

[:lower:]

Lowercase letters

[:print:]

Visible characters and spaces (i.e. Anything except control characters, etc.)

[:punct:]

Punctuation and symbols

[:space:]

All white space characters, including line breaks

[:upper:]

Uppercase letters

[:word:]

Word characters (Letters, Numbers and Underscores)

[:xdigit:]

Hexadecimal digits

UTF-8 Character Classes

The following can be used anywhere in the pattern to match common types of characters:

Note:
This only works for 'OM'=0 on PxPlus 2014.

\p{xx}

A character with the xx property

\P{xx}

A character without the xx property

\X

A Unicode extended grapheme cluster