AppC.htm

Appendix C:

REGEX coding.

Specifications:

^

A circumflex as the first character of the pattern forces matches to beginning of lines.

$

A dollar as the last character of the pattern forces matches to end of lines.

.

A period anywhere in the string matches any single character.

*

A character followed by an asterisk matches zero or more occurrences of that character.

+

A character followed by a plus sign matches one or more occurrences of that character.

-

A character followed by a minus sign optionally matches that character.

[]

A string enclosed in square brackets matches any character in that string, but no others. If the first character of the string is a circumflex the expression matches any character except the characters in the string. A range of characters may be specified by two characters separated by a -.

\<

A backslash followed by an opening < matches the beginning of a word.

\>

A backslash followed by a closing > matches the end of a word.

$

A backslash followed by an opening ( describes the beginning of a tagged sub-expression (see Substitution Expressions, it has no effect on search-only expressions).

$

A backslash followed by a closing ) describes the end of a tagged sub-expression (see Substitution Expressions, it has no effect on search-only expressions).

\

A backslash folowed by any other character quotes that character. This allows a search for a character that is usually a regular expression specifier.

|

A pipe symbol is evaluated as an OR function.

Examples:

^Windows

matches all lines starting with Windows

Grep$

matches all lines ending with Grep

H..p

matches all lines containing Help, Hoop, Harp, etc.

^W.n

matches all lines starting with Win, Won, etc.

\$

matches a dollar sign

fo*

matches f, fo, foo, fooo, etc.

fo+

matches fo, foo, fooo, etc.

[xyz]

matches x, y or z

a[^xyz]c

matches abc, arc and atc but not axc, ayc, or azc

([0-9])

matches (0), (1), (2), (3), (4), (5), (6), (7), (8) and (9)

([0-9]*)

matches (), (0), (123), (2512), etc.

\<[Aa].*\>

matches any non-empty word beginning with either A or a

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^	A circumflex as the first character of the pattern forces matches to beginning of lines.
$	A dollar as the last character of the pattern forces matches to end of lines.
.	A period anywhere in the string matches any single character.
*	A character followed by an asterisk matches zero or more occurrences of that character.
+	A character followed by a plus sign matches one or more occurrences of that character.
-	A character followed by a minus sign optionally matches that character.
[]	A string enclosed in square brackets matches any character in that string, but no others. If the first character of the string is a circumflex the expression matches any character except the characters in the string. A range of characters may be specified by two characters separated by a -.
\<	A backslash followed by an opening < matches the beginning of a word.
\>	A backslash followed by a closing > matches the end of a word.
\(	A backslash followed by an opening ( describes the beginning of a tagged sub-expression (see Substitution Expressions, it has no effect on search-only expressions).
\)	A backslash followed by a closing ) describes the end of a tagged sub-expression (see Substitution Expressions, it has no effect on search-only expressions).
\	A backslash folowed by any other character quotes that character. This allows a search for a character that is usually a regular expression specifier.
\|	A pipe symbol is evaluated as an OR function.

^Windows	matches all lines starting with Windows
Grep$	matches all lines ending with Grep
H..p	matches all lines containing Help, Hoop, Harp, etc.
^W.n	matches all lines starting with Win, Won, etc.
\$	matches a dollar sign
fo*	matches f, fo, foo, fooo, etc.
fo+	matches fo, foo, fooo, etc.
[xyz]	matches x, y or z
a[^xyz]c	matches abc, arc and atc but not axc, ayc, or azc
([0-9])	matches (0), (1), (2), (3), (4), (5), (6), (7), (8) and (9)
([0-9]*)	matches (), (0), (123), (2512), etc.
\<[Aa].*\>	matches any non-empty word beginning with either A or a