第六周作业

第六周作业

1、复制/etc/rc.d/rc.sysinit文件至/tmp目录，将/tmp/rc.sysinit文件中的以至少一个空白字符开头的行的行首加#；
命令：

cp /etc/rc.d/rc.sysinit /tmp/
sed -i 's@^[[:space:]]@#  @g

效果：

[root@liam ~]# cp /etc/rc.d/rc.sysinit /tmp/
[root@liam ~]# ls /tmp
keyring-IFZ3Jm  orbit-gdm  orbit-root  pulse-rsPriwMzVy2z  pulse-vMB549h8T0sT  rc.sysinit  virtual-root.JW5ORZ  yum.log
[root@liam ~]# sed 's@^[[:space:]]@#  @g'   /tmp/rc.sysinit
#!/bin/bash
#
# /etc/rc.d/rc.sysinit - run once at boot time
#
# Taken in part from Miquel van Smoorenburg's bcheckrc.
#
HOSTNAME=$(/bin/hostname)
set -m
if [ -f /etc/sysconfig/network ]; then
#     . /etc/sysconfig/network
fi
if [ -z "$HOSTNAME" -o "$HOSTNAME" = "(none)" ]; then
#     HOSTNAME=localhost
fi

2、复制/boot/grub/grub.conf至/tmp目录中，删除/tmp/grub.conf文件中的行首的空白字符；

命令：

cp /boot/grub/grub.conf /tmp/
sed 's/^[[:space:]]+//' /tmp/grub.conf

效果：

[root@liam ~]# sed 's/^[[:space:]]\+//g' /tmp/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/mapper/vg_liam-lv_root
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-431.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/vg_liam-lv_root rd_NO_LUKS rd_LVM_LV=vg_liam/lv_swap rd_LVM_LV=vg_liam/lv_root rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM LANG=en_US.UTF-8 rhgb quiet
initrd /initramfs-2.6.32-431.el6.x86_64.img
[root@liam ~]#

3、删除/tmp/rc.sysinit文件中的以#开头，且后面跟了至少一个空白字符的行行的#和空白字符

命令：

sed 's/^#[[:space:]]\+//g' /tmp/rc.sysinit

效果：

[root@liam ~]# sed 's/^#[[:space:]]\+//g' /tmp/rc.sysinit
#!/bin/bash
#
/etc/rc.d/rc.sysinit - run once at boot time
#
Taken in part from Miquel van Smoorenburg's bcheckrc.
#
HOSTNAME=$(/bin/hostname)
set -m
if [ -f /etc/sysconfig/network ]; then
. /etc/sysconfig/network
fi
if [ -z "$HOSTNAME" -o "$HOSTNAME" = "(none)" ]; then
HOSTNAME=localhost
fi
if [ ! -e /proc/mounts ]; then
mount -n -t proc /proc /proc
mount -n -t sysfs /sys /sys >/dev/null 2>&1
fi
if [ ! -d /proc/bus/usb ]; then
modprobe usbcore >/dev/null 2>&1 && mount -n -t usbfs /proc/bus/usb /proc/bus/usb
else
mount -n -t usbfs /proc/bus/usb /proc/bus/usb
fi
#remount /dev/shm to set attributes from fstab #669700
mount -n -o remount /dev/shm >/dev/null 2>&1
#remount /proc to set attributes from fstab #984003
mount -n -o remount /proc >/dev/null 2>&1
. /etc/init.d/functions
PLYMOUTH=
[ -x /bin/plymouth ] && PLYMOUTH=yes
Check SELinux status
SELINUX_STATE=
..........

4、为/tmp/grub.conf文件中前三行的行首加#号；

命令：
sed '1,3s/^/#/' /tmp/grub.conf

效果：

[root@liam ~]# sed '1,3s/^/#/' /tmp/grub.conf
## grub.conf generated by anaconda
##
## Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)

5、将/etc/yum.repos.d/CentOS-Media.repo文件中所有的enabled=0或gpgcheck=0的最后的0修改为1；

命令：

sed -i 's/enabled=0/enabled=1/g;s/gpgcheck=0/gpgcheck=1/g' /etc/yum.repos.d/CentOS-Media.repo

效果：

[root@liam ~]# sed 's/enabled=0/enabled=1/g;s/gpgcheck=0/gpgcheck=1/g' /etc/yum.repos.d/CentOS-Media.repo
# CentOS-Media.repo
#
#  This repo can be used with mounted DVD media, verify the mount point for
#  CentOS-6.  You can use this repo and yum to install items directly off the
#  DVD ISO that we release.
#
# To use this repo, put in your DVD and use it with the other repos too:
#  yum --enablerepo=c6-media [command]
#
# or for ONLY the media repo, do this:
#
#  yum --disablerepo=\* --enablerepo=c6-media [command]
[c6-media]
name=CentOS-$releasever - Media
baseurl=file:///media/CentOS/
file:///media/cdrom/
file:///media/cdrecorder/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
[root@liam ~]#

6、每4小时执行一次对/etc目录的备份，备份至/backup目录中，保存的目录名为形如etc-201608300202

[root@liam ~]# crontab -l
0 */4 * * *  tar -cvf  /bakcup/etc-`date +%Y%m%d%H%M%S`.tar  /etc  &>/dev/null
[root@liam ~]#

7、每周2，4，6备份/var/log/messages文件至/backup/messages_logs/目录中，保存的文件名形如messages-20160830

[root@liam ~]# crontab -l
0 0 * * 2,4,6  tar -cvf  /bakcup/messages_logs/messages-`date +%Y%m%d`.tar  /var/log/messages  &>/dev/null
[root@liam ~]#

8、每天每两小时取当前系统/proc/meminfo文件中的所有以S开头的信息至/stats/memory.txt文件中

[root@liam ~]# crontab -l
0 0-23/2 * * *  grep ^S /proc/meminfo >> /stats/memory.txt
[root@liam ~]#

9、工作日的工作时间内，每两小时执行一次echo "howdy"

[root@liam ~]# crontab -l
0 9-17/2 * * 1-5  echo "howdy"
[root@liam ~]#

脚本编程练习
10、创建目录/tmp/testdir-当前日期时间;

#!/bin/bash
#
declare day=`date +%Y%m%d`
mkdir /tmp/testdir-$day

11、在此目录创建100个空文件：file1-file100

#!/bin/bash
#
declare day=`date +%Y%m%d`
mkdir /tmp/testdir-$day
touch /tmp/testdir-$day/file{1..10}

12、显示/etc/passw d文件中位于第偶数行的用户的用户名；

[root@liam bin]# cat passwd2.sh
#!/bin/bash
#
cat /etc/passwd | awk NR%2==0 | cut -d: -f1
[root@liam bin]# bash -x  passwd2.sh
+ cut -d: -f1
+ awk NR%2==0
+ cat /etc/passwd
bin
adm
sync
halt
uucp
games
ftp
dbus
vcsa
rtkit
abrt
nfsnobody
gdm
apache
postfix
sshd
[root@liam bin]#

13、创建10用户user10-user19；密码同用户名；

[root@liam bin]# cat useradd10-19.sh
#!bin/bash
#
for i in {10..19}; do
if  id user$i &> /dev/null ; then
echo "user$i exits"
else
useradd user$i
if [ $? -eq 0 ] ; then
echo user$i | passwd --stdin user$i &> /dev/null
echo "user$i add finish"
fi
fi
done
[root@liam bin]#

14、在/tmp/创建10个空文件file10-file19;

#!/bin/bash
touch /tmp/file{10..19}

15、把file10的属主和属组改为user10，依次类推。

[root@liam bin]# bash -n grant10-19.sh
[root@liam bin]#
[root@liam bin]# cat grant10-19.sh
#!bin/bash
#
touch /tmp/file{10..19}
for i in {10..19}; do
if  id user$i &> /dev/null ; then
echo "user$i exits"
else
useradd user$i
if [ $? -eq 0 ] ; then
echo user$i | passwd --stdin user$i &> /dev/null
echo "user$i add finish"
chmod user$i:user$i /tmp/file$i  &> dev/null
echo "file%i grant to user$i susscess"
fi
fi
done
[root@liam bin]#