utmp structure, but rather one named utmpx (as part of the XSI extension), with specifications ... user fields. Linux defines the utmpx structure to be the same as the utmp structu…utmp structure, but rather one named utmpx (as part of the XSI extension), with specifications ... user fields. Linux defines the utmpx structure to be the same as the utmp structu…utmp structure, but rather one named utmpx (as part of the XSI extension), with specifications ... user fields. Linux defines the utmpx structure to be the same as the utmp structu…