man Pages(4): File Formats

utmp(4)

NAME

utmp, wtmp- utmp and wtmp entry formats

SYNOPSIS

#include <utmp.h>

DESCRIPTION

The utmp database file contains user access and accounting information for commands such as who(1) , write(1) , and login(1) . The wtmp file contains the history of user access and accounting information for the utmp database. The database contained in these files can be manipulated using the getutent() family of functions. Entries in the database are described by the definitions and data structures in <utmp.h> . See getutent(3C) .

USAGE

The utmp and wtmp files are obsolete. They have been replaced by the extended database contained in the utmpx and wtmpx files. See utmpx(4) .

Applications should not access these files directly, but should use the functions described on the getutxent(3C) manual page to interact with these files. Using these extended APIs will ensure that the utmp and utmpx databases are maintained consistently.

FILES

/var/adm/utmp: user access and accounting information (old format)
/var/adm/wtmp: history of user access and accounting information for utmp database (old format)