N33-week 2-Sunflower

1. What are the file management commands on Linux, their common use methods and their related examples
Touch: Create file and Refresh Timestamp
Touch [OPTION]. FILE:
"1" touch-c file name: Refreshes the timestamp of the file if the file already exists, and creates an empty file if the file does not exist
Example:
Touch-c Tmpchi or Touch Tmpchi
No files in directory create empty file:-rw-r--r--. 1 root root 0 Oct 7 14:18 Tmpchi
File in directory refresh timestamp:-rw-r--r--. 1 root root 0 Oct 7 14:21 Tmpchi
"2" touch-a file name: Change only Atime and CTime
Example:
Touch-a Tmpchi
access:2018-10-07 14:21:42.167194043 +0800
modify:2018-10-07 14:21:01.915193580 +0800
change:2018-10-07 14:21:42.167194043 +0800
"3" touch-m file name: Change only Mtime and CTime
Example:
Touch-m Tmpchi
access:2018-10-07 14:21:42.167194043 +0800
modify:2018-10-07 14:23:43.221195437 +0800
change:2018-10-07 14:23:43.221195437 +0800
"4" touch-t [[CC]YY]MMDDHHMM[.SS]: Specify timestamps for Atime and Mtime
Example:
Touch-t 201809081112.13 Tmpchi
access:2018-09-08 11:12:13.000000000 +0800
modify:2018-09-08 11:12:13.000000000 +0800
change:2018-10-07 14:24:55.220196265 +0800

CP: Copying Files or directories
"1" CP [OPTION] ... [-T] SOURCE DEST: Copying files and changing file names
Cp-i: Tips before overwriting
Example:
The file does not exist, a new file is created
Cp/tmp/tmpchi/app/tmpchi.bak
-rw-r--r--. 1 root root 0 Oct 7 14:34/app/tmpchi.bak
-rw-r--r--. 1 root root 0 Oct 7 14:25/tmp/tmpchi
File already exists, overwrite the file (i-I prompt prior to overwrite)
Cp-i/tmp/tmpchi/app/tmpchi.bak
-rw-r--r--. 1 root root 0 Oct 7 14:36/app/tmpchi.bak
-rw-r--r--. 1 root root 0 Oct 7 14:25/tmp/tmpchi
"2" CP [OPTION] ... SOURCE ... DIRECTORY: Copying files without changing file names
Cp-r,-r: Recursively copy directories and all internal content
Example:
Copy a TMP directory in the app directory (-R recursively copies the TMP directory and all internal content)
Cp-r/tmp/app
Drwxr-xr-t. Root root 4096 Oct 7 14:43 tmp
"3" cp-d: Copy Soft connection Name
Example
If you do not add-D, if you copy a directory, the default copy directory's soft connection points to the corresponding original file, not the soft connection itself
Cp/etc/rc/app
-rwxr-xr-x. 1 root root 2617 Oct 7 15:09/APP/RC
lrwxrwxrwx. 1 root root 7 Sep 21:44/ETC/RC-RC.D/RC
Cp-d/etc/rc/app
lrwxrwxrwx. 1 root root-Oct 7 15:13/APP/INIT.D-RC.D/INIT.D
lrwxrwxrwx. 1 root root one Sep 21:32/etc/init.d-rc.d/init.d\\
"4"--preserv
-rw-r--r--. 1 root root 0 Oct 7 15:23/app/tmpchi
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/tmp/tmpchi
CP--preserv=timestamp: Preserve the timestamp of the source file while copying
Example:
Cp/tmp/tmpchi/app/tmpchi--preserv=timestamp
-rw-r--r--. 1 root root 0 Oct 7 15:22/app/tmpchi
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/tmp/tmpchi
CP--preserv=ownership: Preserve the owner of the source file while copying
Example:
Cp/tmp/tmpchi/app/tmpchi--preserv=ownership
-rw-r--r--. 1 cmx CMX 0 Oct 7 15:25/app/tmpchi
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/tmp/tmpchi
CP--preserv=all equivalent to CP-A: archive, preserving all properties of the source file while copying
Example:
Cp-a/tmp/tmpchi/app/tmpchi or Cp/tmp/tmpchi/app/tmpchi--preserv=all
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/app/tmpchi
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/tmp/tmpchi
Example:
CP--backup=numbered: Target exists, backup plus data suffix before overwriting
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22/tmp/tmpchi
-rw-r--r--. 1 root root 0 Oct 7 15:28 Tmpchi
-rw-rw-r--. 1 cmx CMX 0 Oct 7 15:22 tmpchi.~1~

mv: Moving files or renaming file names
"1" mv [OPTION] ... [-T] SOURCE DEST: Move files and change file names
Example:
Move files under the same directory, rename files if files exist
MV Tmpchi Tmpchixx
-rw-r--r--. 1 root root 0 Oct 7 14:25 Tmpchi
-rw-r--r--. 1 root root 0 Oct 7 14:25 Tmpchixx
Move files under different directories, move and rename
Mv/tmp/tmpchi01/app/tmpchixx
-rw-r--r--. 1 root root 0 Oct 7 16:07/tmp/tmpchi01
-rw-r--r--. 1 root root 0 Oct 7 14:36/app/tmpchixx

Rename: Renaming multiple files
Rename [OPTIONS] expression replacement file ...
Example:
-rw-r--r--. 1 root root 0 Oct 7 16:15 F1
-rw-r--r--. 1 root root 0 Oct 7 16:15 f2
-rw-r--r--. 1 root root 0 Oct 7 16:15 f3
-rw-r--r--. 1 root root 0 Oct 7 16:15 f4
-rw-r--r--. 1 root root 0 Oct 7 16:15 f5
Rename F f00 f?
-rw-r--r--. 1 root root 0 Oct 7 16:15 f001
-rw-r--r--. 1 root root 0 Oct 7 16:15 f002
-rw-r--r--. 1 root root 0 Oct 7 16:15 f003
-rw-r--r--. 1 root root 0 Oct 7 16:15 f004
-rw-r--r--. 1 root root 0 Oct 7 16:15 f005

RM: Deleting files or directories
"1" rm-i: Prompt before deletion
Example:
Rm-i Tmpchi
Rm:remove Regular empty file tmpchi‘?<br/>【2】rm -r：递归删除目录<br/>示例：<br/>cp -r /tmp/gconfd-root /app<br/>drwx------. 2 root root 4096 Oct 7 16:23 gconfd-root<br/>rm gconfd-root<br/>rm: cannot remove Gconfd-root ': is a directory
Rm-r Gconfd-root
Rm:descend into directory ' Gconfd-root '?
Enter Y to delete the directory

mkdir: Creating a Folder
"1" mkdir-p: Create subdirectories under directory containing directory
Example:
Mkdir-p Mylinux
Drwxr-xr-x. 2 root root 4096 Oct 7 16:29 Mylinux
"2" Mkdir-m: Creating a directory is directly specifying permissions
Mkdir-m mylinux: Permissions set to file Master readable, write, execute, the same group of users can read and execute, other users do not have access to
Drwxr-x---. 2 root root 4096 Oct 7 16:35 Mylinux
"3" MKDIR-V: Show Details
Example:
Mkdir-v Mylinux
mkdir:created directory ' Mylinux '

2. Bash's work characteristics the command execution status return value and command-line expansion are involved in the content and its example demonstration
"1" feature
alias Command alias: Defines the alias name, which is equivalent to executing the command VALUE alias name= ' value '
History Command History:
-C: Empty command history
-D 5: Delete the 5th command specified in history
-A: Attach all the commands in memory to the disk command file (. bash_history)
-r: Attach all commands in the disk command file to memory history
-N: Append the new command in the disk command file to memory history
-P: Expand the History command parameter into multiple lines (Execute command But history command does not record)
-S: Expands the history command parameter into one line (can forge the command without executing the command, history-s "RM/")
echo Display character: Echo will send the input string to standard output. The output string is separated by white space characters, and the line number is added at the end,
$ () or ' parameters to print the output of one command to another
Example:
[[email protected]/]# echo "Hello Welcome to $ (hostname)"
Hello Welcome to CENTOS6.CMX
Tab key: Command completion, PATH completion
Command 2Tab all subcommands or file completion
Example:
[[email protected]/]# He double-click the TAB key
Head Help Hexdump
./2tab Show all directories below the root directory, including hidden directories
Example:
[Email protected]/]#.
app/dev/lib64/mnt/root/sys/
bin/etc/lost+found/net/sbin/tmp/
boot/home/media/opt/selinux/usr/
. dbus/lib/misc/proc/srv/var/
2Tab current directory subdirectories, excluding hidden directories
Example:
[Email protected]/]#
App etc lost+found Net Sbin tmp
Bin home media opt SELinux usr
Boot lib misc proc srv var
Dev lib64 mnt Root sys
~2tab List of all users
Example:
[Email protected]/]# ~
~abrt/~games/~nobody/~saslauth
~adm ~gdm/~ntp/~shutdown/
~apache/~gopher ~operator/~sshd/
~AVAHI-AUTOIPD ~haldaemon/~postfix/~sync/
~bin/~halt/~pulse ~tcpdump/
~cmx/~lp/~root/~usbmuxd/
~daemon/~mail/~rpc ~UUCP
~dbus/~mysql/~rpcuser/~vcsa/
~ftp ~nfsnobody/~rtkit/
Bash shortcut keys
Ctrl+l=clear: Clear Screen
Ctrl+s: Block Screen output
Ctrl+q: Allow screen output
CTRL + C: Close the current run window
Atl+r: Delete the current entire row
Echo (atl+a) 1000: Output 1000 A
Ctrl + u: Delete from cursor to beginning of command
Ctrl + K: delete from cursor to end of command line
Ctrl + A: The cursor moves to the beginning of the command, which is equivalent to home
Ctrl + E: Cursor moves to the end of the command line, equivalent to end
Ctrl + W: Delete left to the beginning of the word from the cursor
Alt + D: Delete right from cursor to end of word
Ctrl + D: Delete a character at the cursor
Ctrl + H: Delete a character before the cursor

  "2" Command execution status return value use a special variable $ in bash? To save the execution status result of the previous command: 0 for success, 1-255 for failure example: [[[email protected] app] #rm null; echo $?rm:remove regular empty file ' null '? Y0[[email protected] app]# RM null; echo $?rm:cannot remove ' null ': No such file or directory1 ' 3 ' command line expand to some of the symbols that bash can interpret To replace some of the arguments in the command. ~: Expand to the user's home directory; Example: Switch to home directory [[[email protected] app]# CD ~[[email protected] ~]# pwd/root{}: Can host a comma-delimited list, and expand it to multiple paths; Example: Create f01,f02,f03 three files under/tmp/mylinux directory [[email protected]/] #touch/tmp/mylinux/f0{1,2,3}-rw-r--r--. 1 root root 0 Oct 7 16:57 f01-rw-r--r--. 1 root root 0 Oct 7 16:57 f02-rw-r--r--. 1 root root 0 Oct 7 16:57 f03  

3. Use the command line expansion function to complete the following exercise:
(1) to create A/tmp directory: a_c,a_d,b_c,b d
Mkdir/tmp/{a,b} {c,d}
(2 Create the/tmp/mylinux directory:
mylinux/
|---bin
|---boot
|----Grub
|---dev
|---etc
| |----RC.D
| | | --INIT.D
| |----sysconfig
| |---network-scripts
|---lib
| |--modules
|---lib64
|---proc
|--- Sbin
|---sys
MKDIR-P/tmp/mylinux/{bin,boot/grub,dev,etc/{rc.d/init.d,sysconfig/network-scripts},lib/ Modules,lib64,proc,sbin,sys}

4, what are the file metadata information, what do they mean, and how do I view it? How to modify timestamp information for a file.
Stat file name view meta data (metadata) information:
File:a_c
size:4096 blocks:8 IO block:4096 directory
device:fd00h/ 64768d inode:1048579 links:2
Access: (0755/drwxr-xr-x) Uid: (0/root) Gid: (0/root)
Context:unconfined_u:objec T_r:user_tmp_t:s0
access:2018-10-07 12:01:31.600097235 +0800
modify:2018-10-07 12:01:31.600097235 +0800
change:2018-10-07 12:01:31.600097235 +0800
Three time stamps:
Access time: Access times, atime, read file contents
Modify Time: Modified, Mtime, Change file contents (data)
Change time: CTime, metadata changes
View atime and Mtime,ctime time: Stat file name
Touch-a file name: Change only Atime and CTime (touch-a a_c)
touch-m file name: Change only Mtime and CTime (touch-m a_c)
Touch-t [[CC]YY]MMDDHHMM[.SS]: Specify timestamps for Atime and Mtime (touch-t 201809081112.13 a_c)
Touch-c file name: Refreshes the timestamp of the file if the file already exists, and creates a new file if the file does not exist

5, how to define the alias of a command, how to reference the execution result of another command in the command?
Command alias: Alias
Defines the alias as if, which is equivalent to executing the command value
Alias if= ' Ifcofig '
Command reference:
Alias pwd= ' ifconfig ': Perform pwd display ifconfig results

6. Display all files or directories in the/var directory that start with L, end with a lowercase letter, and have at least one digit (can have other characters) appear in the middle
ls-d/var/l[[:d igit:]] [[: Lower:]] or ls-d/var/l[0-9][[: Lower:]]

7. Displays files or directories that start with any number and end with a non-number in the/etc directory
ls-d/etc/[[:d igit:][^[:d igit:]] or ls-d/etc/[0-9][^0-9]

8, display in/etc directory, start with a non-letter, followed by a letter and any other length of any character file or directory
ls-d/etc/[^[:alpha:]][[:alpha:]] or ls-d/etc/[^a-za-z][a-za-z]

9. In the/tmp directory, create a file that starts with Tfile, followed by the current date and time, with a filename such as: tfile-2016-05-27-09-32-22
touch/tmp/tfile- date +%Y-%m-%d-%H-%M-%S or touch/tmp/tfile-date +%F-%H-%M-%S

10. Copy all the files or directories in the/etc directory to the/tmp/mytestl directory that begin with P and do not end with a number
Cp-a/etc/p[[: Alpha:]]/tmp/mytest1 or cp/etc/p[^[:d igit:]]/tmp/mytest1

11. Copy all files or directories ending with. d in/etc directory to the/tmp/mytest2 directory
Cp-a/etc/*.d/tmp/mytest2

12. Copy all files in the/etc directory that begin with L or M or N and end with. conf to the/TMP/MYTEST3 directory
Cp-a/etc/[lmn]*.conf/tmp/mytest3

N33-week 2-Sunflower