<regex.h>

The <regex.h> include file defines the following regular expression functions:

regcomp() regerror() regexec() regfree()

The <regex.h> include file also declares the regmatch_t type, the regex_t type, which is capable of storing a compiled regular expression, and the following macros:

Values of the cflags parameter of the regcomp() function:

REG_BASIC
REG_EXTENDED
REG_ICASE
REG_NEWLINE
REG_NOSUB

Values of the eflags parameter of the regexec() function:

REG_NOTBOL
REG_NOTEOL

Values of the errcode parameter of the regerror() function:

REG_NOMATCH
REG_BADPAT
REG_ECOLLATE
REG_ECTYPE
REG_EESCAPE
REG_ESUBREG
REG_EBRACK
REG_EPAREN
REG_EBRACE
REG_BADBR
REG_ERANGE
REG_ESPACE
REG_BADRPT
REG_ECHAR
REG_EBOL
REG_EEOL
REG_ECOMP
REG_EEXEC
REG_LAST

These declarations and definitions are not available when LOCALETYPE(*CLD) is specified on the compilation command.

Note: The regular expressions supported by regcomp() and regexec() follow the specification described here: "http://www.opengroup.org/onlinepubs/007908799/xbd/re.html".