1) the user su is targeting
2) 执行 su 命令的用户 (或者他可能属于的组)
文件格式为：以 # 开头的行视为注视，并被忽略；
Where to-id is either the word ALL, a list of usernames delimited by "," or the words ALL EXCEPT followed by a list of usernames delimited by ",".
from-id is formatted the same as to-id except the extra word GROUP is recognized. ALL EXCEPT GROUP is perfectly valid too. Following GROUP appears one or more group names, delimited by ",". It is not sufficient to have primary group id of the relevant group, an entry in /etc/group(5) is necessary.
# sample /etc/suauth file # # A couple of privileged usernames may # su to root with their own password. # root:chris,birddog:OWNPASS # # Anyone else may not su to root unless in # group wheel. This is how BSD does things. # root:ALL EXCEPT GROUP wheel:DENY # # Perhaps terry and birddog are accounts # owned by the same person. # Access can be arranged between them # with no password. # terry:birddog:NOPASS birddog:terry:NOPASS #