Megeedu Linux+python Advanced Operations 3 period five weeks

1. Display the default shell of root, fedora or User1 user on the current system;

[[email protected] ~]# useradd fedora          #添加用户fedora [[email protected] ~]# useradd user1           #添加用户user1 [[email protected] ~]# egrep  ' ^ ( Root|fedora|user1) '  /etc/passwd | cut -d: -f1,7                                         #使用表达式 (Root|fedora|user1) Find root, Fedora, or user1root:/bin/bashfedora:/bin/bashuser1:/bin/bash[[email protected] ~]# 

2. Find the line with a set of parentheses after a word in the/etc/rc.d/init.d/functions file, such as: Hello ();

[Email protected] ~]# egrep-o "^[_[:alpha:]]+\ (\)"/etc/rc.d/init.d/functions #使用 [: Alpha:] Special character set matching [a-z,a-z]

3. Use the echo command to output an absolute path, using grep to remove its base name;

Extension: Take out its path name

[Email protected] ~]# echo "/home/etc/" | Egrep-o "[^/]+/?$" | Cut-d "/"-f1

4, find out the results of the ifconfig command between 1-255 numbers;

[Email protected] ~]# Ifconfig | Egrep-o ' ([1-9]|[ 1-9][0-9]| [0-2] [0-5] [0-5]) '

5, Challenge: Write a mode, can match the reasonable IP address;

#以IPV4地址为例: #现在的IP网络使用32位地址, in dotted decimal notation, such as 192.168.0.1. #地址格式为: IP address = Network address + host address #这里不做细化, simple match satisfies host address is not full 0 or full 1, ie (1-255). (0-255). (0-255). (1-254) can # "([1-9]|[ 1-9][0-9]| [0-2] [0-5] [0-5]). ([0-9]| [1-9] [0-9]| [0-2] [0-5] [0-5]). ([0-9]| [1-9] [0-9]| [0-2] [0-5] [0-5]). ([1-9]| [1-9] [0-9]| [0-2] [0-5] [0-4]) " [email protected] ~]# cat TestIP.txt 2.34.67.991.0.0.11.22.0.01.24.0.255192.168.999.254192.167.255.255[[email Protected] ~]# egrep "\< ([1-9]|[ 0-9][1-9]| [0-2] [0-5] [0-5]) \. ([0-9]| [1-9] [0-9]| [0-2] [0-5] [0-5]) \. ([0-9]| [1-9] [0-9]| [0-2] [0-5] [0-5]) \. ([1-9]| [1-9] [0-9]| [0-2] [0-5] [0-4]) \> "TestIP.txt 2.34.67.991.0.0.1[[email protected] ~]#

6, Challenge: Write a pattern, can match out all the email address;

#邮箱地址一般分为三大部分, username @ domain # The first part of the user name, can contain numbers, letters, underscores, and does not start with special characters. #第二部分为 @, available @ Direct Match # Part Three is a domain name that can contain letters, numbers, underscores, and "." And does not start with a special character. For example: qq.com, 163.com[[email protected] ~]# cat mail.txt #创建mail. txt file, handwritten several e-mail addresses. [Email protected] [Email protected] [Email protected] [email protected]_djfie.dlfl.com[[email protected] ~]# egrep "^[[:alnum:]][_[:alnum:]]*@[[:alnum:]][_[:alnum:]]*\. [[: Alnum:]] "mail.txt [email protected][email protected][[email protected] ~]#

7. Find the main root of the/var directory, and belong to all files or directories of mail;

[[email protected] ~]# find/var-user root-group mail #使用find命令加-user and-group options specify their owner group/var/spool/mail[[email Prot  Ected] ~]# find/var-user root-group mail-ls #使用选项-ls View Details 262439 4 drwxrwxr-x 2 root mail 4096 September 5 18:46/var/spool/mail

8, find the current system does not belong to the main or group of files;

[[email protected] ~]# Find/-nouser-o-nogroup #选项-nouser means no owner,-nogroup means no group,-O indicates Condition ' or '

Further: Find files or directories that are not owned by the master or group on the current system and have been visited in the last 3 days;

[[email protected] ~]# Find/-nouser-o-nogroup-atime-3 #选项-atime-3 to find files or directories that have been visited in the last 3 days

9, find all the users in/etc directory have write permission files;

[Email protected] ~]# find/etc/-perm-222-ls #使用选项-perm Find #-222 According to permissions: every A class of objects must also have a permission standard assigned to it; #/mode: the permission of any class of (U,g,o) object can only be one match

10. Find all files that are larger than 1M in/etc directory and are of normal file type;

[[email protected] ~]# find /etc -size +1m -type f -ls                           #选项-size : Specify find File Size                           #选项-type: Specifying File types                          #   f:  General Documents                          #    d:  Catalog Files                          #   l:  Symbolic Link File                          #    s: Socket file                          #   b:  Block device Files                           #   c:  Character device Files                          #   p:  Piping Files

11, find/etc/init.d/directory, all users have execute permission, and other users have write permission files;

[Email protected] ~]# Find/etc/init.d-perm-113-ls

12. Find files that do not belong to root, bin or hadoop in the/usr directory;

[Email protected] ~]# find/usr-not \ (-user root-o-user bin-o-user hadoop \)-ls[[email protected] ~]# find/usr/-   Not-user root-a-not-user bin-a-not-user hadoop #选项-not condition non-#选项-a For conditions and

13, to find at least one type of/etc/directory Users do not have write permission files;

[Email protected] ~]# Find/etc-not-perm-111-ls

14. Find files whose contents have been modified and not rooted or Hadoop for the last week in/etc directory;

[Email protected] ~]# find/etc/-mtime-7-a-not \ (-user root-o-user hadoop \) #选项-mtime lookup means Files or directories that have been modified during the

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Megeedu Linux+python Advanced Operations 3 period five weeks