????1.???????μ??????????????????????
1 [root@server test]# useradd rr  ##???????rr
2 [root@server test]# id rr
3 uid=510(rr) gid=511(rr) groups=511(rr)
4 [root@server ~]# ls -la /home/rr/    ##??/home/rr????????????
5 total 28
6 drwx------   2 rr   rr   4096 Dec 26 09:41 .
7 drwxr-xr-x. 12 root root 4096 Dec 26 09:41 ..
8 -rw-r--r--   1 rr   rr     18 Jul 24 02:55 .bash_logout
9 -rw-r--r--   1 rr   rr    176 Jul 24 02:55 .bash_profile
10 -rw-r--r--   1 rr   rr    124 Jul 24 02:55 .bashrc
11 -rw-r--r--   1 rr   rr    658 Nov 10 20:27 .zshrc
12 -rw-r--r--   1 rr   rr     15 Dec 25 11:03 readme.txt
13 [root@server ~]# cd /home/rr
14 [root@server rr]# rm -f .bash
15 .bash_history  .bash_logout   .bash_profile  .bashrc
16 [root@server rr]# rm -f .bash*   ##????????bash???????????
17 [root@server ~]# su - rr   ##?л???rr???
18 -bash-4.1$   ##???????????
19 ##?????
20 -bash-4.1$ cp /etc/skel/.bash* /home/rr  ##??/etc/skel????bash???????????????????????????
21 -bash-4.1$ logout
22 [root@server ~]# su - rr    ##?????л???rr?????
23 [rr@server ~]$
1 ### 2 [root@server /home 09:56:56]#PS1='[u@h w ]$' ##?????????????Ч??????д??/etc/profile?????
????2.???/etc/login.efs?????????????
1 # *REQUIRED*
2 #   Directory where mailboxes reside?? _or_ name of file?? r
3 elative to the
4 #   home directory.  If you _do_ define both?? MAIL_DIR tak
5 es precedence.
6 #   QMAIL_DIR is for Qmail
7 #
8 #QMAIL_DIR      Maildir
9 MAIL_DIR        /var/spool/mail    ##mail????·??
10 #MAIL_FILE      .mail
11 # Password aging controls:
12 #
13 #       PASS_MAX_DAYS   Maximum number of days a passw
14 ord may be used.
15 #       PASS_MIN_DAYS   Minimum number of days allowed
16  between password changes.
17 #       PASS_MIN_LEN    Minimum acceptable password le
18 ngth.
19 #       PASS_WARN_AGE   Number of days warning given b
20 efore a password expires.
21 #
22 PASS_MAX_DAYS   99999    ##??????Ч????????
23 PASS_MIN_DAYS   0   ##С??Ч??
24 PASS_MIN_LEN    5    ##????С????
25 PASS_WARN_AGE   7  ##????????
26
27 # Min/max values for automatic uid selection in userad
28 d
29 #
30 UID_MIN                   500
31 UID_MAX                 60000      ##???ID???С
32
33 #
34 # Min/max values for automatic gid selection in groupa
35 dd
36 #
37 GID_MIN                   500
38 GID_MAX                 60000    ##??ID???С
39
40 # If useradd should create home directories for users
41 by default
42 # On RH systems?? we do. This option is overridden with
43  the -m flag on
44 # useradd command line.
45 #
46 CREATE_HOME     yes   ##?????????????????????????-m??????????
47
48 # The permission mask is initialized to this value. If
49  not specified??
50 # the permission mask will be initialized to 022.
51 UMASK           077     ##??????UMASK
52
53 # This enables userdel to remove user groups if no mem
54 bers exist.
55 #
56 USERGROUPS_ENAB yes ##????????????????
????3.????/etc/default/useradd????????е??????
????1 [root@server ~]# cat /etc/default/useradd   
????2 # useradd defaults file
????3 GROUP=100
????4 HOME=/home   ##??????????????/home?С?
????5 INACTIVE=-1  ##??????????????????-1?????????
????6 EXPIRE=    ##?????????????????????????
????7 SHELL=/bin/bash  ##?????????????shell????
????8 SKEL=/etc/skel  ##????????????????????????·???????????/etc/skel????????????useradd?????????????????μ???????????????????????и?????
????9 CREATE_MAIL_SPOOL=yes  ##????mail???
?????????
????useradd -c??-u??-G??-s??-d??????????????
???????????????????shell???????????????????
??????????oldboy6????????????????????HandsomeBoy??UID????806????????????root??oldboy??sa???
??????shell?????/bin/sh?????ü????/oldboy6??
???????????????
1 ###????????????sa
2 [root@server ~]# grep "sa" /etc/group
3 vcsa:x:69:
4 saslauth:x:76:
5 sa:x:512:
6 [root@server ~]# grep -o "sa" /etc/group   ##???????“sa”????????????
7 sa
8 [root@server ~]# useradd -c "HandsomeBoy" -u 806 -G root??oldboy??sa -s /bin/sh -d /oldboy6 oldboy6
9 ##???
10 -c:?????????
11 -u:????UID??
12 -G:????????????
13 -s:????????shell
14 -d:????????????
15 ###???????
16 [root@server ~]# grep "oldboy6" /etc/passwd
17 oldboy6:x:806:806:HandsomeBoy:/oldboy6:/bin/sh
18 [root@server ~]# id oldboy6
19 uid=806(oldboy6) gid=806(oldboy6) groups=806(oldboy6)??0(root)??512(sa)??513(oldboy)