本周作业内容：
1、列出当前系统上所有已经登录的用户的用户名，注意：同一个用户登录多次，则只显示一次即可。
[root@captain ~]# who | cut -d' ' -f1 | sort -u
icheck
oracle
root
2、取出最后登录到当前系统的用户的相关信息。
[root@captain shell]# cat getuserinfo.sh
#!/bin/bash
# author: Felix Ruan
# get user basic information
# date:20160820
# v1.0
if [ `id -u` -ne 0 ]; then
echo "only root can execute this script"
exit 1
fi
readonly User=${1:-`last | head -1 | cut -d' ' -f1`}
readonly PASSWD=/etc/passwd
function getuginfo()
{
echo "basic information for last login user: $1"
echo "user name: `id -nu $1`, uid: `id -u $1`"
echo "group name: `id -ng $1`, gid: `id -g $1`"
}
function gethome()
{
echo "user home: `grep -w ^$1 $PASSWD | cut -d':' -f6`"
}
function getshell()
{
local ushell=`grep -w "^$1" $PASSWD | cut -d':' -f7`
case $ushell in
*sh)
echo "user shell: $ushell";;
"")
echo "user shell: /bin/sh";;
*)
;;
esac
}
function pwdinfo()
{
echo "password expiry information:"
chage -l $1 | egrep -e '(Password|Account) expires' -e 'Maximum number'
}
function main()
{
getuginfo $1
echo '-------------------------------'
gethome $1
echo '-------------------------------'
getshell $1
echo '-------------------------------'
pwdinfo $1
echo
}
main $User
[root@captain shell]# sh getuserinfo.sh
basic information for last login user: oracle
user name: oracle, uid: 500
group name: dba, gid: 500
-------------------------------
user home: /root/oracle
-------------------------------
user shell: /bin/bash
-------------------------------
password expiry information:
Password expires : never
Account expires : never
Maximum number of days between password change : 99999
3、取出当前系统上被用户当作其默认shell的最多的那个shell。
[root@captain ~]# awk -F":" 'BEGIN{printf("Shell\t\tCount\n")}\
> {a[$NF]++}END{\
> for(i in a)\
> if(i~/sh$/)\
> {if(a[i]>cnt) cnt=a[i];sh=i}\
> {printf("%s\t%d\n", sh, cnt)}}' /etc/passwd
Shell Count
/bin/bash 7
[root@captain ~]#
4、将/etc/passwd 中的第三个字段数值最大的后10个用户的信息全部改为大写后保存至/tmp/maxusers.txt文件中。
[root@captain ~]# cat /etc/passwd | sort -t':' -k3 -n | tail -10 > /tmp/maxusers.txt
[root@captain ~]# cat /tmp/maxusers.txt
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
abrt:x:173:173::/etc/abrt:/sbin/nologin
dhcpd:x:177:177:DHCP server:/:/sbin/nologin
nginx:x:497:497:nginx user:/var/cache/nginx:/sbin/nologin
mongod:x:498:498:mongod:/var/lib/mongo:/bin/false
saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin
oracle:x:500:500::/home/oracle:/bin/bash
icheck:x:501:500::/home/icheck:/bin/bash
nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/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。
[root@captain ~]# for nic in `ifconfig -a | cut -d' ' -f1 | grep -v 'lo'`
> do
> ifconfig $nic | grep 'inet addr' |\
> awk -v var=$nic -F'[:| ]+' '{printf("%s: %s\n", var, $4)}'
> done
eth0: 192.168.162.134
eth2: 192.168.1.10
eth2:0: 192.168.10.10
[root@captain ~]#
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。
[root@captain etc]# ls *.conf
asound.conf gai.conf libuser.conf numad.conf sos.conf
autofs.conf grub.conf logrotate.conf oddjobd.conf sudo.conf
autofs_ldap_auth.conf gssapi_mech.conf ltrace.conf pm-utils-hd-apm-restore.conf sudo-ldap.conf
cas.conf host.conf mke2fs.conf prelink.conf sysctl.conf
cgconfig.conf idmapd.conf mongod.conf readahead.conf Trolltech.conf
cgrules.conf kdump.conf named.conf request-key.conf updatedb.conf
cgsnapshot_blacklist.conf krb5.conf nfsmount.conf resolv.conf warnquota.conf
dracut.conf latrace.conf nsswitch.conf rsyslog.conf xinetd.conf
elinks.conf ld.so.conf ntp1.conf sestatus.conf yp.conf
fprintd.conf libaudit.conf ntp.conf smartd.conf yum.conf
[root@captain etc]# ls *.conf | tr 'a-z' 'A-Z' > /tmp/etc.conf
[root@captain etc]# cat /tmp/etc.conf
ASOUND.CONF
AUTOFS.CONF
AUTOFS_LDAP_AUTH.CONF
CAS.CONF
CGCONFIG.CONF
CGRULES.CONF
CGSNAPSHOT_BLACKLIST.CONF
DRACUT.CONF
ELINKS.CONF
FPRINTD.CONF
GAI.CONF
GRUB.CONF
GSSAPI_MECH.CONF
HOST.CONF
IDMAPD.CONF
KDUMP.CONF
KRB5.CONF
LATRACE.CONF
LD.SO.CONF
LIBAUDIT.CONF
LIBUSER.CONF
LOGROTATE.CONF
LTRACE.CONF
MKE2FS.CONF
MONGOD.CONF
NAMED.CONF
NFSMOUNT.CONF
NSSWITCH.CONF
NTP1.CONF
NTP.CONF
NUMAD.CONF
ODDJOBD.CONF
PM-UTILS-HD-APM-RESTORE.CONF
PRELINK.CONF
READAHEAD.CONF
REQUEST-KEY.CONF
RESOLV.CONF
RSYSLOG.CONF
SESTATUS.CONF
SMARTD.CONF
SOS.CONF
SUDO.CONF
SUDO-LDAP.CONF
SYSCTL.CONF
TROLLTECH.CONF
UPDATEDB.CONF
WARNQUOTA.CONF
XINETD.CONF
YP.CONF
YUM.CONF
7、显示/var目录下一级子目录或文件的总个数。
[root@captain ~]# ls /var/
account crash db ftp lib lock mail nis preserve spool www
cache cvs empty games local log named opt run tmp yp
[root@captain ~]# ls /var/ | wc -l
22
8、取出/etc/group文件中第三个字段数值最小的10个组的名字。
[root@captain etc]# sort -t':' -k3 -n /etc/group | head -10 | cut -d':' -f1
root
bin
daemon
sys
adm
tty
disk
lp
mem
kmem
9、将/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。
[root@captain ~]# cat /etc/fstab /etc/issue > /tmp/etc.test
[root@captain ~]# cat /tmp/etc.test
#
# /etc/fstab
# Created by anaconda on Sun Feb 28 19:13:12 2016
#
# 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/VolGroup-lv_root / ext4 defaults 1 1
UUID=269efa02-c94a-42b2-8088-e223080e9f87 /boot ext4 defaults 1 2
/dev/mapper/VolGroup-lv_swap swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
CentOS release 6.6 (Final)
Kernel \r on an \m
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练习：
(1)、创建组distro，其GID为2016；
[root@captain ~]# groupadd -g 2016 distro
(2)、创建用户mandriva, 其ID号为1005；基本组为distro；
[root@captain ~]# useradd -u 1005 -g distro mandriva
(3)、创建用户mageia，其ID号为1100，家目录为/home/linux;
[root@captain ~]# useradd -u 1100 -d /home/linux mageia
(4)、给用户mageia添加密码，密码为mageedu；
[root@captain ~]# echo 'mageedu' | passwd --stdin mageia
Changing password for user mageia.
passwd: all authentication tokens updated successfully.
(5)、删除mandriva，但保留其家目录；
[root@captain ~]# userdel mandriva
[root@captain ~]# ls -d /home/mandriva/
/home/mandriva/
(6)、创建用户slackware，其ID号为2002，基本组为distro，附加组peguin；
[root@captain ~]# groupadd peguin
[root@captain ~]# useradd -u 2002 -g distro -G peguin slackware
(7)、修改slackware的默认shell为/bin/tcsh；
[root@captain ~]# grep '^slackware' /etc/passwd
slackware:x:2002:2016::/home/slackware:/bin/bash
[root@captain ~]# chsh -s /bin/tcsh slackware
Changing shell for slackware.
Shell changed.
[root@captain ~]# grep '^slackware' /etc/passwd
slackware:x:2002:2016::/home/slackware:/bin/tcsh
(8)、为用户slackware新增附加组admins；
[root@captain home]# id slackware
uid=2002(slackware) gid=2016(distro) groups=2016(distro),2017(peguin)
[root@captain ~]# groupadd admins
[root@captain ~]# usermod -aG admins slackware
[root@captain home]# id slackware
uid=2002(slackware) gid=2016(distro) groups=2016(distro),2017(peguin),2018(admins)
(9)、为slackware添加密码，且要求密码最短使用期限为3天，最长为180天，警告为3天；
[root@captain ~]# echo "magedu123" | passwd --stdin slackware
Changing password for user slackware.
passwd: all authentication tokens updated successfully.
[root@captain ~]# chage -l slackware
Last password change : Aug 20, 2016
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7
[root@captain ~]# chage -m 3 -M 180 -W 3 slackware
[root@captain ~]# chage -l slackware
Last password change : Aug 20, 2016
Password expires : Feb 16, 2017
Password inactive : never
Account expires : never
Minimum number of days between password change : 3
Maximum number of days between password change : 180
Number of days of warning before password expires : 3
(10)、添加用户openstack，其ID号为3003, 基本组为clouds，附加组为peguin和nova；
[root@captain ~]# groupadd clouds
[root@captain ~]# groupadd nova
[root@captain ~]# useradd -u 3003 -g clouds -G peguin,nova openstack
[root@captain ~]# id openstack
uid=3003(openstack) gid=2019(clouds) groups=2019(clouds),2017(peguin),2020(nova)
(11)、添加系统用户mysql，要求其shell为/sbin/nologin；
# 系统上已有mysql用户，使用MySQL代替
[root@captain ~]# useradd -r -s /sbin/nologin MySQL
[root@captain ~]# grep '^MySQL' /etc/passwd
MySQL:x:496:496::/home/MySQL:/sbin/nologin
(12)、使用echo命令，非交互式为openstack添加密码。
[root@captain ~]# echo 'magedu123' | passwd --stdin openstack
Changing password for user openstack.
passwd: all authentication tokens updated successfully.