Perl-compatible Regular Expressions (PCRE)

The HTML documentation for PCRE comprises the following pages:

pcre   Introductory page
pcreapi   PCRE's native API
pcrebuild   Options for building PCRE
pcrecallout   The callout facility
pcrecompat   Compability with Perl
pcregrep   The pcregrep command
pcrepartial   Using PCRE for partial matching
pcrepattern   Specification of the regular expressions supported by PCRE
pcreperform   Some comments on performance
pcreposix   The POSIX API to the PCRE library
pcreprecompile   How to save and re-use compiled patterns
pcresample   Description of the sample program
pcretest   The pcretest command for testing PCRE

There are also individual pages that summarize the interface for each function in the library:

pcre_compile   Compile a regular expression
pcre_config   Show build-time configuration options
pcre_copy_named_substring   Extract named substring into given buffer
pcre_copy_substring   Extract numbered substring into given buffer
pcre_exec   Match a compiled pattern to a subject string
pcre_free_substring   Free extracted substring
pcre_free_substring_list   Free list of extracted substrings
pcre_fullinfo   Extract information about a pattern
pcre_get_named_substring   Extract named substring into new memory
pcre_get_stringnumber   Convert captured string name to number
pcre_get_substring   Extract numbered substring into new memory
pcre_get_substring_list   Extract all substrings into new memory
pcre_info   Obsolete information extraction function
pcre_maketables   Build character tables in current locale
pcre_study   Study a compiled pattern
pcre_version   Return PCRE version and release date