Marco 2016 new Linux+python high-end operation fifth Week

Content of this week's job:

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

# no Fedora, User1 users, add fadora,user1 simulation Environment [[email protected] ~]# useradd-s/sbin/nologin Fedora && useradd-s/bin/sh user1# add Fadora, user1 user, and specify a different default Shell[[email protected] ~]# getent passwd fedorafedora:x:1001:1001::/home/fedora:/ Sbin/nologin[[email protected] ~]# getent passwd user1user1:x:1002:1002::/home/user1:/bin/sh# filter/etc/passwd root, Fedora or User1 user, cut displays its corresponding default Shell[[email protected] ~]# egrep "^ (root|fedora|user1)"/etc/passwd | Cut-d:-f7/bin/bash/sbin/nologin/bin/sh

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

# Filter each line, match all letters, and then follow a set of parentheses with the line # using EGREP to extend the regular, () need to escape [[email protected] ~]# Egrep-o "[[: Alpha:]]+\ (\)]/etc/rc.d/init.d/ functions# or [[email protected] ~]# Grep-o "[[: Alpha:]]\+ ()"/etc/rc.d/init.d/functions

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

# matches the base name, which is the last/after file name, exactly matches with the-o option, matches the end of [^/], [[email protected] ~]# echo "/etc/sysconfig/network-scripts/ifcfg-eth0" | Grep-o ' [^/]\+$ ' Ifcfg-eth0

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Extension: Take out its path name

# Match path name, exact match with-o option, match last/previous content [[email protected] ~]# echo "/etc/sysconfig/network-scripts/ifcfg-eth0" | Grep-o ' ^/.*/'/etc/sysconfig/network-scripts/# then take the final/also remove [[email protected] ~]# echo "/etc/sysconfig/network-scripts /ifcfg-eth0 "| Grep-o ' ^/.*/' | Grep-o ' ^/.*[^/] '/etc/sysconfig/network-scripts

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

# Find the number between 1-255, use the-o option to exact match, [1-9] Find 1-9,[1-9][0-9] Find out 10-99,1[0-9]{2} find out 100-199,2[0-5]{2} Find out 200-255# sort, go to heavy [email Protected] ~]# # Ifconfig | Egrep-o ' \b (2[0-5]{2}|1[0-9]{2}|[ 1-9][0-9]| [1-9]) \b ' | Sort-n-U

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

# Class A address range: 1.0.0.1-126.255.255.254 Class B Address range: 128.0.0.1-191.255.255.254# Class C address range: 192.0.0.1-223.255.255.254 Class D address range: 224.0.0.1-239.255.255.254# Class E address range: 240.0.0.1-255.255.255.254 127.x.x.x is a reserved address, used for cyclic testing with the # Match range of 1-255.0-255.0-255.1-254# Ifconfig | Egrep-o "(2[0-5]{2}|1[0-9]{2}|[ 1-9][0-9]| [1-9]) \. ((2[0-5]{2}|1[0-9]{2}| [1-9] [0-9]| [0-9]) \.) {2}\< (2[0-5][0-4]|1[0-9]{2}|[ 1-9][0-9]| [1-9]) \> "

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

# email address, match user name @ Mail server, username can be number or letter, server name is letter or number, top-level domain is letter # Add some test email address [[email protected] ~]# cat >/tmp/test_mail.txt << eof[email protected][email protected][email protected][email protected][email protected][email Protected]EOF # Egrep-o "[[: Alnum:]][email protected][[:alnum:]]+\. [[: alpha:]]+] [[email protected] ~]# Egrep-o "[[: Alnum:]][email protected][[:alnum:]]+\. [[: alpha:]]+]/tmp/test_mail.txt

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

# Find/var-user Root-group mail[[email protected] var]# find/var-user root-group mail-ls3153 0 drwxrwxr-x 2 ro OT Mail SEP 2 09:33/var/spool/mail

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

# Find/\ (-nouser-o-nogroup \) # Create a few test files, visually compare [[email protected] ~]# useradd user2[[email protected] ~]# Su-user2[[em AIL protected] ~]$ cd/tmp[[email protected] tmp]$ touch Test{1..3}.txt[[email protected] tmp]# chown root test2.txt [[EMA Il protected] tmp]# chown. root test3.txt [[email protected] tmp]# userdel-r user2

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# show some content [[email protected] tmp]# Find/\ (-nouser-o-nogroup \)-ls | Head

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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;

# Find/\ (-nouser-o-nogroup \)-atime-3# display part [[email protected] tmp]# Find/\ (-nouser-o-nogroup \)-atime-3-L s | Head

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

# All users satisfy write permission at the same time, use -222# find/etc/-perm-222

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

# find/etc/-size +1m-type F

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

# Find/etc/init.d-perm-113[[email protected] tmp]# find/etc/init.d-perm-113-ls33709906 0 lrwxrwxrwx 1 root Root 09:39/ETC/INIT.D-RC.D/INIT.D

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

# FIND/USR! \ (-user root-o-user bin-o-user hadoop \) or # FIND/USR! -user Root! -user bin! -user Hadoop

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

#-222 is all users have write permission to use! Take the opposite, is in addition to all users have write permission files, is at least one kind of user is no write permission # FIND/ETC! -perm-222

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

# FIND/ETC-MTIME-7! \ (-user root-o-user hadoop \) or # FIND/ETC-MTIME-7! -user Root! -user Hadoop

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Marco 2016 new Linux+python high-end operation fifth Week