PCRE2 - Perl-compatible regular expressions (revised API) .rs #include <pcre2.h>

 int pcre2_get_error_message(int errorcode, PCRE2_UCHAR *buffer,  " PCRE2_SIZE bufflen);" 

. .rs This function provides a textual error message for each PCRE2 error code. Compilation errors are positive numbers; UTF formatting errors and matching errors are negative numbers. The arguments are: errorcode an error code (positive or negative) buffer where to put the message bufflen the length of the buffer (code units) The function returns the length of the message in code units, excluding the trailing zero, or the negative error code PCRE2_ERROR_NOMEMORY if the buffer is too small. In this case, the returned message is truncated (but still with a trailing zero). If errorcode does not contain a recognized error code number, the negative value PCRE2_ERROR_BADDATA is returned.

There is a complete description of the PCRE2 native API in the HREF
pcre2api
page and a description of the POSIX API in the HREF
pcre2posix
page.