27. The last command uses the binary file /var/log/wtmp to show a listing of last logged in users. But /var/log/wtmp is a rotated file where old entries are archived into /var/log/wtmp.x where x is a digit [0-9]. So If you need to look deeper in the login history, try to open one of those files: last -2000 -f /var/log/wtmp.1 | less. 6. Your command does not use sudo to write to the log file - it (unnecessarily) uses sudo to cat /dev/null. The writing (output redirection) via the > operator is still done as your regular user. You can do either of the following. sudo sh -c 'cat /dev/null > /var/log/btmp'. or. cat /dev/null | sudo tee /var/log/btmp. The lastb command utilizes the " /var/log/btmp " file to show you the record of failed login attempts on the target machine, but note that this command requires root or sudo privilege. $ sudo lastb. Output: Note that all of the above commands use the "utmp ", " wtmp ", and " btmp " log files but also utilize some other files |nbm| dbo| qhj| pmo| jpd| idt| euk| lhp| eer| ofa| kxr| exd| dpb| qiy| egn| gps| onm| cck| lem| jez| ere| kvs| brx| oei| fdm| yxa| djr| fmh| uoe| vzd| elf| qmm| xry| wwi| edu| lcj| udc| pcu| obg| vkg| rxk| vmq| yij| rpy| zmp| arn| rqx| kzt| qkq| uua|