?第五周作業
1、顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行；
[root@localhost ~]# grep -E "^[[:space:]]+" /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet initrd /initramfs-2.6.32-431.el6.x86_64.img [root@localhost ~]# grep "^[[:space:]]\+" /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet initrd /initramfs-2.6.32-431.el6.x86_64.img
2、顯示/etc/rc.d/rc.sysinit文件中以#開頭，后面跟至少一個空白字符，而后又有至少一個非空白字符的行；
[root@localhost ~]# grep "^#[[:space:]]\+[^[:space:]]\+" /etc/rc.d/rc.sysinit # /etc/rc.d/rc.sysinit - run once at boot time # Taken in part from Miquel van Smoorenburg's bcheckrc. # Check SELinux status # Print a text banner. # Only read this once. # Initialize hardware # Set default affinity # Load other user-defined modules # Load modules (for backward compatibility with VARs) # Configure kernel parameters # Set the hostname. # Sync waiting for storage. # Device mapper & related initialization # Start any MD RAID arrays that haven't been started yet # Remount the root filesystem read-write. # Clean up SELinux labels # If relabeling, relabel mount points. # Mount all other filesystems (except for NFS and /proc, which is already # mounted). Contrary to standard usage, # filesystems are NOT unmounted in single user mode. # The 'no' applies to all listed filesystem types. See mount(8). # Update quotas if necessary # Check to see if a full relabel is needed # Initialize pseudo-random number generator # Configure machine if necessary. # Clean out /. # Do we need (w|u)tmpx files? We don't set them up, but the sysadmin might... # Clean up /var. # Clean up utmp/wtmp # Clean up various /tmp bits # Make ICE directory # Start up swapping. # Set up binfmt_misc # Boot time profiles. Yes, this should be somewhere else. # Now that we have all of our basic modules loaded and the kernel going, # let's dump the syslog ring somewhere so we can find it later # create the crash indicator flag to warn on crashes, offer fsck with timeout # Let rhgb know that we're leaving rc.sysinit [root@localhost ~]# grep -E "^#[[:space:]]+[^[:space:]]+" /etc/rc.d/rc.sysinit # /etc/rc.d/rc.sysinit - run once at boot time # Taken in part from Miquel van Smoorenburg's bcheckrc. # Check SELinux status # Print a text banner. # Only read this once. # Initialize hardware # Set default affinity # Load other user-defined modules # Load modules (for backward compatibility with VARs) # Configure kernel parameters # Set the hostname. # Sync waiting for storage. # Device mapper & related initialization # Start any MD RAID arrays that haven't been started yet # Remount the root filesystem read-write. # Clean up SELinux labels # If relabeling, relabel mount points. # Mount all other filesystems (except for NFS and /proc, which is already # mounted). Contrary to standard usage, # filesystems are NOT unmounted in single user mode. # The 'no' applies to all listed filesystem types. See mount(8). # Update quotas if necessary # Check to see if a full relabel is needed # Initialize pseudo-random number generator # Configure machine if necessary. # Clean out /. # Do we need (w|u)tmpx files? We don't set them up, but the sysadmin might... # Clean up /var. # Clean up utmp/wtmp # Clean up various /tmp bits # Make ICE directory # Start up swapping. # Set up binfmt_misc # Boot time profiles. Yes, this should be somewhere else. # Now that we have all of our basic modules loaded and the kernel going, # let's dump the syslog ring somewhere so we can find it later # create the crash indicator flag to warn on crashes, offer fsck with timeout # Let rhgb know that we're leaving rc.sysinit [root@localhost ~]#
3、打出netstat -tan命令執行結果中以‘LISTEN’，后或跟空白字符結尾的行；
[root@localhost ~]# netstat -tan |grep "LISTEN[[:space:]]*" tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:25 :::* LISTEN
4、添加用戶bash, testbash, basher, nologin (此一個用戶的shell為/sbin/nologin)，而后找出當前系統上其用戶名和默認shell相同的用戶的信息；
[root@localhost ~]# grep -E "^([^:]+\>).*\1$" /etc/passwd sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt bash:x:500:500::/home/bash:/bin/bash nologin:x:503:503::/home/nologin:/sbin/nologin
5、顯示當前系統上root、fedora或user1用戶的默認shell；
[root@localhost ~]# grep -E "(root|fedora|user1)" /etc/passwd |cut -d: -f7 /bin/bash /sbin/nologin
6、找出/etc/rc.d/init.d/functions文件中某單詞后面跟一組小括號的行，形如：hello()；
[root@localhost ~]# grep -E "[[:alnum:]]\>+\(\)" /etc/rc.d/init.d/functions
fstab_decode_str() {
checkpid() {
__readlink() {
__fgrep() {
__umount_loop() {
__umount_loopback_loop() {
__pids_var_run() {
__pids_pidof() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
echo_success() {
echo_failure() {
echo_passed() {
echo_warning() {
update_boot_stage() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {
get_numeric_dev() {
is_ignored_file() {
is_true() {
is_false() {
apply_sysctl() {
key_is_random() {
find_crypto_mount_point() {
init_crypto() {
7、使用echo命令輸出一個絕對路徑，使用grep取出其基名；
echo /etc/rc.d/init.d/functions | grep -o "[^/]*/*$" functions
擴展：取出其路徑名
[root@localhost ~]# echo /etc/rc.d/init.d/functions | grep -o "/.*/" /etc/rc.d/init.d/
8、找出ifconfig命令結果中的1-255之間數字；
[root@localhost ~]# ifconfig |grep --color -E -o "<\([1-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]\)\>"
29
52
192
168
44
23
192
168
44
25
25
25
25
80
20
29
95
64
150
52
84
34
27
100
50
51
70
49
44
43
47
43
127
25
128
164
36
68
68
68
68
9、挑戰題：寫一個模式，能匹配合理的IP地址；
[root@localhost ~]# ifconfig eth0 |grep -oE "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}"
192.168.44.23
192.168.44.255
255.255.255.0
10、挑戰題：寫一個模式，能匹配出所有的郵件地址；
[a-z,A-Z,0-9,_]*@[a-z,A-Z,0-9,_]*\.[a-z,A-Z,0-9]*
11、查找/var目錄下屬主為root，且屬組為mail的所有文件或目錄；
find /var/ -user root -a -group mai
12、查找當前系統上沒有屬主或屬組的文件；
find / -nouser -o -nogroup
進一步：查找當前系統上沒有屬主或屬組，且最近3天內曾被訪問過的文件或目錄；
find / -nouser -a -nogroup -a -type f -a mtime -3 find / \( -nouser -o -nogroup \) -a -type f -a mtime -3
13、查找/etc目錄下所有用戶都有寫權限的文件；
find /etc/ -perm -222
14、查找/etc目錄下大于1M，且類型為普通文件的所有文件；
[root@localhost ~]# find /etc/ -size +1M -a -type f /etc/seLinux/targeted/modules/active/policy.kern /etc/seLinux/targeted/policy/policy.24
15、查找/etc/init.d/目錄下，所有用戶都有執行權限，且其它用戶有寫權限的文件；
find /etc/init.d/ -perm -113
16、查找/usr目錄下不屬于root、bin或hadoop的文件；
find /usr/ -not -user root -a -not -user bin -not -user hadoop find /usr/ -not \( -user root -o -user bin -o -user hadoop \)
17、查找/etc/目錄下至少有一類用戶沒有寫權限的文件；
find /etc/ -not -perm /2
18、查找/etc目錄下最近一周內其內容被修改過，且不屬于root或hadoop的文件
find /etc/ -not -user root -a -not -user hadoop -a -mtime -7