https://manpages.ubuntu.com/manpages/focal/man3/getutmp.3.html
Ubuntu Manpage: getutmp, getutmpx - copy utmp structure to utmpx, and vice versa
copy utmp structure to utmpx, and vice versa
https://www.dre.vanderbilt.edu/Doxygen/6.2.3/html/libace-doc/a01719.html
ACE: os_utmpx.h File Reference
h fileaceosreference