Megeedu Linux+python Advanced Operations 3 period four weeks

1, the Replication/etc/skel directory is/home/tuser1, requires/home/tuser1 and its internal files belong to the group and other users do not have any access rights.

[[email protected] ~]# cp -r /etc/skel/ / home/tuser1         #使用cp命令带-R option: recursively replicate directories and all internal content; [[email protected]  ~]# ll /home/ | grep tuser1         #查看/ home/tuser1  Directory file Details drwxr-xr-x. 2 root      root     4096 8 Month   23 22:06 tuser1[[email protected] ~]# chmod  go= /home/tuser1         #修改文件属组 (g) and Other (o) permissions [[email protected]  ~]# ll /home/ | grep tuser1        # View modified file permissions drwx------.  2 root      root    4096  8 month   23 22:06 tuser1[[email protected] ~]# 

2. Edit the/etc/group file and add the group Hadoop.

[[email protected] ~]# vim/etc/group #使用vim编辑器打开/etc/group File # Use the letter "G" to jump to the end of the file, press "O" below the current line to insert into the input mode. #编辑内容 "hadoop:x:2021:", press "ESC" to exit the input mode and enter edit mode. #键入 ":" Into the command line mode, enter "Wq" to save the exit. Or, type "ZZ" in edit mode to save the exit. [Email protected] ~]# Cat/etc/group | grep Hadoop #查看编辑结果hadoop: X:2021:[[email protected] ~]# #其中 "hadoop:x:2021:" One ":" As a delimiter, divided into four paragraphs, respectively, corresponding to the # Group name: Group Password: GID: The current group as an additional group User list (delimiter is comma)

3. Manually edit the/etc/passwd file to add a new line, adding user Hadoop, whose basic group ID is the Hadoop group ID number; its home directory is/home/hadoop.

#首先了解下/etc/passwd file content format [[email protected] ~]# cat/etc/passwd #查看/etc/passwd file contents root:x:0:0:root:/root:/bin/bash# This article To hold the user and its attribute information, using the ":" Delimiter, divided into 7 fields # format: name:password:uid:gid:gecos:directory:shell# (1) Name: username. # (2) Password: the password is represented by an X (encrypted, stored in the shadow file/etc/shadow), shadow file can only be read as root. # (3) uid:uid (user ID). # (4) Gid:gid group identification. # (5) GECOS: User information, usermod-c specified when modifying or creating a user. # (6) Directory: Home directory. # (7) Shell: Login using the shell. [[email protected] ~]# vim/etc/passwd #使用vim编辑器打开, #使用字母 "G" jump to the end of the file, press "O" below the current line to insert into the input mode. #编辑内容 "Hadoop:x:1001:2021::/home/hadoop:/bin/bash", Save exit

4. Copy the/etc/skel directory as/home/hadoop, which requires that the genus Group and other users of the Hadoop directory be modified without any access rights.

[[email protected] ~]# cp-r/etc/skel//home/hadoop #复制/etc/skel directory for/home/hadoop[[email protected] ~]# chmod-r go= /home/hadoop #修改hadoop目录的属组和其它用户没有任何访问权限. #修改目录权限命令chmod, the format is as follows #chmod [OPTION] ... Octal-mode file...# [option]:-r: Recursive Modify permissions #chmod [option] ... Mode[,mode] ... FILE ... #修改一类用户的所有权限: # mode:u=[,g=,o=] or go= or a= ("=" followed by permission type r,w,x) #修改一类用户某位或某些位权限 # mode:u+ U-Add or modify Permissions #chmod [OPTION]. . --reference=rfile file...# refer to rfile file for permission, change file to the same rfile;

5, modify the/home/hadoop directory and all the internal files of the owner of Hadoop, belong to Hadoop group.

[Email protected] ~]# chown-r hadoop:hadoop/home/hadoop #修改文件的属主: Chown#chown [OPTION] ... [OWNER] [: [GROUP]] file...# [OPTION]:-r: Recursive # Usage: (Note: ":" In the command is available.) replace;) # OWNER only modifies the master # Owner:group modified owner: Genus Group #: Group only modifies genus Group

6. Display the lines in the/proc/meminfo file beginning with uppercase or lowercase s, in two ways;

#方法一:[[email protected] ~]# grep -i  ' ^s '  /proc/meminfo# method two:[[email  protected] ~]# grep ^[ss] /proc/meminfo  #使用命令grep   #grep  [OPTIONS]  Pattern [file ...] #    [options]: #             --color=auto:  match to the text shaded display;#       -v:  display lines that cannot be matched to the pattern;        -i:  ignore character capitalization; #       -o:   Displays only the matched string;#       -q:  silent mode and does not output any information;#        -A #:after,  show match to Line and after # line #       -b #:  before,  Front # line #       -c #:context,  before and after each # line #   &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;-E: Using Egrep; extending regular Expressions #    pattern:#             .:   matches any single character;#             []:  matches any single character in the specified range #            [^ ]: matches any single character outside the specified range #             ': Single quote, strong reference #              "": double quotes, weak reference #             *: Matches the preceding character any number of times, including 0 times #             .*: Any character of any length;#             \?: matches the preceding character 0 or 1 times; the preceding is optional; #            \+ : matches the preceding character at least 1 times; #            \{m\}: Matches the preceding character m times;#             \{m,n\}: Matches the preceding character at least m times, up to N times;#        &nbspPosition anchor: #            ^: Anchor at the beginning of the line; the leftmost;#   for the pattern           $: End of line anchoring; the rightmost;#      for the pattern        ^PATTERN$:  for pattern matching whole line;#             ^$:  Empty Line;#             ^[[:space:]]*$: Blank line #            \<  or  \b: The first anchor of the word; for the left;#            \>  of the word pattern or  \b: the ending anchor; for the right side of the word pattern; #            \<pattern\ Match whole word;#         regular special character set #             [[:d igit:]]    : Matching numbers  [0-9]#             [[:lower:]]  : Matching lowercase letters  [a-z]#       &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;[[:UPPER:]]&NBSP;&NBSP: Match capital letters  [A-Z]#             [[:p unct:]]  : Match Special characters #             [[:space:]]  : Match spaces #        &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;[[:ALPHA:]]&NBSP;&NBSP;&NBSP: Matching Letters  [a-zA-Z]#      &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;[[:ALNUM:]]&NBSP;&NBSP: Match letters and numbers  [0-9a-za-z]

7. Display the default shell of the/etc/passwd file as a non-/sbin/nologin user;

[Email protected] ~]# grep-v '/sbin/nologin$ '/etc/passwd

8. Display the user whose default shell is/bin/bash in/etc/passwd file;

[[email protected] ~]# grep '/bin/bash$ '/etc/passwd | Cut-d:-f1

9. Find out one or two digits in the/etc/passwd file;

[[email protected] ~]# grep ' \<[0-9]\{1,2\}\> '/etc/passwd

10. Display the line beginning with at least one blank character in/boot/grub/grub.conf;

[Email protected]lhost ~]# grep ' ^[[:space:]]\+ '/boot/grub/grub.conf

11, the display/etc/rc.d/rc.sysinit file with the beginning of #, followed by at least one white space character, and then have at least one non-whitespace character line;

[[email protected] ~]# grep ' ^[#[:space:]\+].*[^[:space:]\+]$ '/etc/rc.d/rc.sysinit

12, the Netstat-tan command execution results in the "LISTEN", followed by or with a blank character end of the line;

[Email protected] ~]# Netstat-tan | grep ' lished.*[:space:]*$ '

13, add user bash, Testbash, basher, Nologin (this one user's shell is/sbin/nologin), and then find the current system on its user name and the default shell of the same user information;

[Email protected] ~]# useradd bash && useradd testbash && useradd basher && useradd-s/sbin/nolo Gin Nologin [[email protected] ~]# grep "^\ ([[: alnum:]]\+\>\). *\1$"/etc/passwd or use [[email protected] ~]# egrep "^ ([[: alnum:]]+\>). *\1$ "/etc/passwd

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Megeedu Linux+python Advanced Operations 3 period four weeks