# display current user's crontab
crontab -l
# edit current user's crontab
crontab -e
# delete current user's crontab
crontab -r
# display <username>'s crontab
crontab -l -u <username>
# edit <username>'s crontab
crontab -e -u <username>
# delete <username>'s crontab
crontab -r -u <username>
# populate crontab from file contents
crontab -l -u <username> | cat - <filename> | crontab -u <username> -