#include <pcre2.h>
int pcre2_set_newline(pcre2_compile_context *ccontext, uint32_t value);
This function sets the newline convention within a compile context. This specifies which character(s) are recognized as newlines when compiling and matching patterns. The second argument must be one of:
PCRE2_NEWLINE_CR Carriage return only
PCRE2_NEWLINE_LF Linefeed only
PCRE2_NEWLINE_CRLF CR followed by LF only
PCRE2_NEWLINE_ANYCRLF Any of the above
PCRE2_NEWLINE_ANY Any Unicode newline sequence
PCRE2_NEWLINE_NUL The NUL character (binary zero)
The result is zero for success or PCRE2_ERROR_BADDATA if the second argument is invalid.
There is a complete description of the PCRE2 native API in the pcre2api page and a description of the POSIX API in the pcre2posix page.