Slick V3.3 manual Minimal versus Maximal Matching

	Find and Replace with Regular
	Expressions
Example		Description
UNIX regular expression:		Replace occurrences of "if" and "while" with "xify"
Search for: (ifwhile)		and "xwhiley." Unmatched groups are null. Note:
Replace with: x\1y\2		The UNIX syntax \2 (SlickEdit syntax #1, Brief syn-
SlickEdit® regular expression:		tax \1) is replaced with null.
Search for: {ifwhile}
Replace with: x#0y#1
Brief regular expression:
Search for: {{if}while}}
Replace with: x\0y\1
UNIX regular expression:		Reverse text on lines containing a comma. Lines
Search for: ^(.*?),(.*)$		with "abc,def" will be changed to "def,abc." Notice
Replace with: \2,\1		that the UNIX regular expression search string uses
SlickEdit regular expression:		a minimal matching operator *? so that the comma
		actually matches the first comma in the line and not
Search for: ^{?*},{?*}$		the last.
Replace with: #1,#0
Brief regular expression:
Search for: ^{*},{*}$
Replace with: \1,\0

Minimal versus Maximal Matching

If you are using tagged expressions or regular expressions to perform a search and replace, you need to understand the difference between the minimal and maximal operators.

Take, for example, a line of text which contains a DOS file name: \path1\path2\path3\name.ext.

The regular expression ^\\.*?\\ (UNIX), ^\\?*\\ (SlickEdit® ), or <\\*\\ (Brief) will match the string \path1\.

The regular expression ^\\.*\\ (UNIX), ^\\?@\\ (SlickEdit), or <\\\:*\\ (Brief), which uses the maximal oper- ator, matches the string \path\path2\path3\.

As a rule of thumb, you will usually want to use the minimal matching operators *? (UNIX), * (SlickEdit), or

@(Brief) and +? (UNIX), + (SlickEdit/Brief) after a less-specific regular expression such as . (UNIX) or ? (SlickEdit/Brief).

You will usually want to use the maximal matching operators after a regular expression which matches something more specific. For example, to search for a string of digits and prefix each string of digits with the character $, you would specify the following in the Replace tab of the Find and Replace view:

•UNIX regular expression: Search for: ([0-9]+) Replace with: $\1

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