### <regex.h>

The <regex.h> include file declares the type size_t and defines the following regular expression functions:

regcomp | regerror
regexec | regfree

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

REG_EXTENDED:
REG_ICASE
REG_NEWLINE
REG_NOSUB Values of the cflags parameter of the regcomp function

REG_NOTBOL:
REG_NOTEOL Values of the eflags parameter of the regexec function

REG_* Values of the errcode parameter of the regerror function