Configuring the WSM using Device Manager

Rules for using standard regular expressions

Use the following rules when creating patterns for string matching:

• Use only one layer of parenthesis.
• Use only a single $ (match at end of line), which must appear at the end of the string. For example, abc$*def is not supported.
• The size of the user input string must be 40 characters or less.
• The size of the regular expression structure after compilation cannot exceed 43 bytes for load balancing strings and 23 bytes for Web Cache Redirection. The size of regular expression after compilation varies, based on regular expression characters used in the user input string.
• Use / at the beginning of the regular expression. Otherwise a regular expression will have * prefixed to it automatically. For example, html/*\.htm appears as *html/*\.htm.
• Incorrectly or ambiguously formatted regular expressions are rejected instantly. For example:

­	Where a + or ? follows a special character like the *

­	A single + or ? sign

­	Unbalanced brackets and parenthesis

See also:

• Regular expression matching
• Standard regular expression characters
• Configuring regular expressions
• Content-intelligent switching
• Server load balancing basics
• Virtual server load balancing