XPath has a number of basic functions for working with strings:
starts-with(main_string, prefix_string)
contains(containing_string, contained_string)
substring(string, offset, length)
substring-before(string, marker-string)
substring-after(string, marker-string)
string-length(string)
normalize(string)
translate(string, replaced_text, replacement_text)
concat(string1, string2, ...)
The strings these operate on are generally the values of nodes
These may be part of any select expression, but are most commonly used
in xsl:value-of
.
XPath does not, however, provide full Perl or POSIX regular expressions.
XSLT/XPath 2.0 might add these