pcap_strerror(3) on FreeBSD
The text 523d87cd8884, as FreeBSD 10.4-RELEASE, FreeBSD 10.3-RELEASE, FreeBSD 10.2-RELEASE, FreeBSD 10.1-RELEASE, FreeBSD 10.0-RELEASE, FreeBSD 9.3-RELEASE, FreeBSD 9.2-RELEASE, FreeBSD 9.1-RELEASE, FreeBSD 9.0-RELEASE shipped it.
convert an errno value to a string