用户创建及权限管理

1.列出当前系统上所有已经登录的用户的用户名,注:同一个用户登录多次,则只显示一次即可。

who | cut -d ‘ ‘ -f1 | sort -u

[root@localhost ~]# who
danry    :0           2017-07-16 23:20 (:0)
danry    pts/0        2017-07-16 23:23 (192.168.1.2)
root     pts/1        2017-07-16 23:30 (192.168.1.2)
[root@localhost ~]# 
[root@localhost ~]# 
[root@localhost ~]# who | cut -d ' ' -f1 | sort -u
danry
root
[root@localhost ~]#

2.列出最后登录到当前系统的用户的相关信息。

(1),last | head -1

[root@localhost ~]# last | head -1
root     pts/3        192.168.1.2      Mon Jul 17 01:05   still logged in   
[root@localhost ~]# who
danry    :0           2017-07-16 23:20 (:0)
danry    pts/0        2017-07-16 23:23 (192.168.1.2)
root     pts/1        2017-07-16 23:30 (192.168.1.2)
danry    pts/2        2017-07-16 23:46 (192.168.1.2)
root     pts/3        2017-07-17 01:05 (192.168.1.2)
[root@localhost ~]#

(2),id last | head -1 | cut -d ‘ ‘ -f1`

[root@localhost ~]# id  `last | head -1 | cut -d ' ' -f1`
uid=1000(danry) gid=1000(danry) groups=1000(danry),10(wheel)
[root@localhost ~]# ^C

[root@localhost ~]# who
danry    :0           2017-07-16 23:20 (:0)
danry    pts/0        2017-07-16 23:23 (192.168.1.2)
root     pts/1        2017-07-16 23:30 (192.168.1.2)
danry    pts/2        2017-07-16 23:46 (192.168.1.2)
[root@localhost ~]#

3.列出当前系统上被用户当作其默认shell的最多的那个shell。

(1),echo $0

[root@localhost ~]# echo $0
-bash
[root@localhost ~]#

(2),echo $SHELL

[root@localhost ~]# echo $SHELL
/bin/bash
[root@localhost ~]#

4.讲/etc/passwd中的第三个字段数值最大的10个用户的信息全部改为大写后保存至/tmp/maxusers.txt文件中。

sort -t: -k3 -n -r /etc/passwd | head -10 | tr ‘a-z’ ‘A-Z’

[root@localhost ~]# sort -t: -k3 -n -r /etc/passwd | head -10 | tr 'a-z' 'A-Z' > /tmp/maxusers.txt
[root@localhost ~]#
[root@localhost ~]# cat /tmp/maxusers.txt 
NFSNOBODY:X:65534:65534:ANONYMOUS NFS USER:/VAR/LIB/NFS:/SBIN/NOLOGIN
DANRY:X:1000:1000:DANRY:/HOME/DANRY:/BIN/BASH
SYSTEMD-BUS-PROXY:X:999:998:SYSTEMD BUS PROXY:/:/SBIN/NOLOGIN
SYSTEMD-NETWORK:X:998:997:SYSTEMD NETWORK MANAGEMENT:/:/SBIN/NOLOGIN
POLKITD:X:997:996:USER FOR POLKITD:/:/SBIN/NOLOGIN
UNBOUND:X:996:994:UNBOUND DNS RESOLVER:/ETC/UNBOUND:/SBIN/NOLOGIN
COLORD:X:995:993:USER FOR COLORD:/VAR/LIB/COLORD:/SBIN/NOLOGIN
GEOCLUE:X:994:991:USER FOR GEOCLUE:/VAR/LIB/GEOCLUE:/SBIN/NOLOGIN
SASLAUTH:X:993:76:SASLAUTHD USER:/RUN/SASLAUTHD:/SBIN/NOLOGIN
LIBSTORAGEMGMT:X:992:990:DAEMON ACCOUNT FOR LIBSTORAGEMGMT:/VAR/RUN/LSM:/SBIN/NOLOGIN

5.取出当前主机的IP地址,提示:对ifconfig命令的结果进行切分。

ifconfig | grep inet | grep -v 127.0.0.1 | head -1 | cut -d’ ‘ -f10

[root@localhost ~]# ifconfig | grep  inet  | grep -v 127.0.0.1 | head -1 | cut -d' ' -f10
192.168.1.1
[root@localhost ~]#

6.列出/etc目录下所有以.conf结尾的文件的文件名,并将其名字转换为大写后保存至/tmp/etc.conf文件中。

ls /etc/*.conf | tr ‘a-z’ ‘A-Z’ > /tmp/etc.conf

[root@localhost ~]# ls /etc/*.conf | tr 'a-z' 'A-Z'  > /tmp/etc.conf
[root@localhost ~]# 
[root@localhost ~]# cat /tmp/etc.conf 
/ETC/ASOUND.CONF
/ETC/AUTOFS.CONF
/ETC/AUTOFS_LDAP_AUTH.CONF
/ETC/BRLTTY.CONF
/ETC/CGCONFIG.CONF
/ETC/CGRULES.CONF
/ETC/CGSNAPSHOT_BLACKLIST.CONF
/ETC/CHRONY.CONF
/ETC/DLEYNA-SERVER-SERVICE.CONF
/ETC/DNSMASQ.CONF
/ETC/DRACUT.CONF
/ETC/E2FSCK.CONF
/ETC/FPRINTD.CONF
/ETC/FUSE.CONF
/ETC/HBA.CONF
/ETC/HOST.CONF
/ETC/IDMAPD.CONF
/ETC/IPSEC.CONF
/ETC/KDUMP.CONF
/ETC/KRB5.CONF
/ETC/KSMTUNED.CONF
/ETC/LD.SO.CONF
/ETC/LIBAUDIT.CONF
/ETC/LIBUSER.CONF
/ETC/LOCALE.CONF
/ETC/LOGROTATE.CONF
/ETC/MAN_DB.CONF
/ETC/MKE2FS.CONF
/ETC/MTOOLS.CONF
/ETC/NFSMOUNT.CONF
/ETC/NSSWITCH.CONF
/ETC/NTP.CONF
/ETC/NUMAD.CONF
/ETC/ODDJOBD.CONF
/ETC/PBM2PPA.CONF
/ETC/PNM2PPA.CONF
/ETC/RADVD.CONF
/ETC/REQUEST-KEY.CONF
/ETC/RESOLV.CONF
/ETC/RSYNCD.CONF
/ETC/RSYSLOG.CONF
/ETC/SESTATUS.CONF
/ETC/SOS.CONF
/ETC/SUDO.CONF
/ETC/SUDO-LDAP.CONF
/ETC/SYSCTL.CONF
/ETC/TCSD.CONF
/ETC/UPDATEDB.CONF
/ETC/USB_MODESWITCH.CONF
/ETC/VCONSOLE.CONF
/ETC/WVDIAL.CONF
/ETC/YUM.CONF
[root@localhost ~]#

7.显示/var目录下一级子目录或文件的总个数。

ls /var/ | wc -l

[root@localhost ~]# ls /var/ | wc -l
22
[root@localhost ~]#


[root@localhost ~]# ls /var/
account  cache  db     games   kerberos  local  log   nis  preserve  spool   tmp
adm      crash  empty  gopher  lib       lock   mail  opt  run       target  yp
[root@localhost ~]#

8.取出/etc/group 文件中的第三个字段最小的10个组的名字。

sort /etc/group -t ‘:’ -k3 -n | head -10

[root@localhost ~]# sort /etc/group -t ':' -k3 -n | head -10
root:x:0:
bin:x:1:
daemon:x:2:
sys:x:3:
adm:x:4:
tty:x:5:
disk:x:6:
lp:x:7:
mem:x:8:
kmem:x:9:
[root@localhost ~]#

9.讲/etc/fstab和/etc/issue文件的内容合并为同一个内容后保存至/tmp/etc.test文件中。

(1),cat /etc/fstab > /tmp/etc.test , cat /etc/issue >> /tmp/etc.test

[root@localhost ~]# cat /etc/fstab  > /tmp/etc.test
[root@localhost ~]# cat /etc/issue >> /tmp/etc.test 
[root@localhost ~]# cat /tmp/etc.test 

#
# /etc/fstab
# Created by anaconda on Tue Jul 11 07:26:54 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root /                       xfs     defaults        0 0
UUID=d6b40b2e-f1d4-44d7-9f7d-603a0a6e13b5 /boot                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0
\S
Kernel \r on an \m

[root@localhost ~]#

(2),cat /etc/{fstab,issue} > /tmp/etc.test

[root@localhost ~]# rm -rf /tmp/etc.test 
[root@localhost ~]# cat /etc/{fstab,issue} > /tmp/etc.test 
[root@localhost ~]# cat /tmp/etc.test 

#
# /etc/fstab
# Created by anaconda on Tue Jul 11 07:26:54 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root /                       xfs     defaults        0 0
UUID=d6b40b2e-f1d4-44d7-9f7d-603a0a6e13b5 /boot                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0
\S
Kernel \r on an \m

[root@localhost ~]#

10.请总结描述用户和组管理类命令的使用方法并完成以下联系:

(1),创建distro,其中GID为2016;

groupadd -g 2016 distro

[root@localhost ~]# groupadd  -g 2016 distro
[root@localhost ~]# tail -1 /etc/group
distro:x:2016:
[root@localhost ~]#

(2),创建用户mandriva,其中ID号为1005;基本组为distro;

useradd -g distro -u 1005 mandriva

[root@localhost ~]# useradd -g distro -u 1005 mandriva
[root@localhost ~]# tail -1 /etc/passwd
mandriva:x:1005:2016::/home/mandriva:/bin/bash
[root@localhost ~]#

(3),创建用户mageia,其中ID号为1100,家目录为/home/linux;

useradd -u 1100 -1 /home/linux mageia

[root@localhost ~]# useradd -u 1100 -d /home/linux mageia
[root@localhost ~]# tail -1 /etc/passwd
mageia:x:1100:1100::/home/linux:/bin/bash
[root@localhost ~]#

(4),给用户mageia添加密码,密码为mageedu;

echo mageedu | passwd –stdin mageia

[root@localhost ~]# echo mageedu | passwd --stdin mageia
Changing password for user mageia.
passwd: all authentication tokens updated successfully.
[root@localhost ~]#

(5),删除mandriva,但保留其家目录;

userdel mandriva

[root@localhost ~]# userdel mandriva
[root@localhost ~]# ls /home/
danry  linux  mandriva
[root@localhost ~]# grep mandriva /etc/passwd
[root@localhost ~]#

(6),创建用户slackware,其ID号为2002,基本组为distro,附加组peguin;

useradd -u 2002 -G distro,peguin slackware

[root@localhost ~]# useradd  -u 2002 -G distro,peguin slackware
[root@localhost ~]# tail -1 /etc/passwd
slackware:x:2002:2002::/home/slackware:/bin/bash
[root@localhost ~]# id slackware
uid=2002(slackware) gid=2002(slackware) groups=2002(slackware),2016(distro),2017(peguin)
[root@localhost ~]#

(7),修改slackware的默认shell为/bin/tosh;

usermod -s /bin/tcsh slackware

[root@localhost ~]# usermod -s /bin/tcsh slackware
[root@localhost ~]# id slackware
uid=2002(slackware) gid=2002(slackware) groups=2002(slackware),2016(distro),2017(peguin)
[root@localhost ~]# grep slackware /etc/passwd
slackware:x:2002:2002::/home/slackware:/bin/tcsh
[root@localhost ~]#

(8),为用户slackware新增附加组admins;

[root@localhost ~]# usermod -G adminis slackware
[root@localhost ~]# id slackware
uid=2002(slackware) gid=2002(slackware) groups=2002(slackware),2018(adminis)
[root@localhost ~]#

原创文章,作者:N27_Danry,如若转载,请注明出处:http://www.178linux.com/81613

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评论列表(1条)

  • 马哥教育
    马哥教育 2017-07-26 23:51

    思路清晰,易懂,是一篇不错的文章,继续加油~