Linux Common management commands use

1. What are the file management commands on Linux, their commonly used methods and their related examples?

Common commands: LS, CD, PWD, mkdir, CP, RM, MV, Touch, cat, more, less, head, tail, Du, WC

LS:-A&NBSP: Lists all the files in the current directory, together with the hidden file, but excludes  .  and     these two directories-d : Lists only the directory itself, not the file data in the directory  -h : List the file capacity in a human-readable way (such as  GB, KB , etc.)  -i  : List  inode  number,inode  the next chapter will introduce  -l : Long data string list, including file properties and permissions and so on data-r : Listed along with subdirectory content, equals all files in that directory will be displayed  CD: example [[email protected] ~]# cd /home/    # Switch to home directory [[email protected] home]# cd -       #返回切换到home前的目录/ ROOT[[EMAIL PROTECTED] ~]# CD&NBSP, .... /        #切换到上一级目录 [[email protected] /]# cd ~           #切换当前用户的home目录pwd:p wd  Display current directory-L: Show current directory-P: Displays the actual physical address of the current directory example [[ email protected] bxx]# pwd/opt/bxx[[email protected] bxx]# pwd -p/home/bss# Pwd -p shows the actual physical address, not the mkdir:-m created by the soft connection: Set the permission mode (like chmod) instead of rwxrwxrwx  minus UMASK-P: Create the upper-level directory of the target directory when needed, But even if these directories already exist and are not treated as error-V: Each time a new directory is created, an example of information is displayed[[email protected] ~]# mkdir rice    #创建目录 [[email protected] ~]#  mkdir -m a=rw rice    #创建指定属性的目录 [[Email protected] ~]# mkdir  -p 111/rice/backup   #这里我个人是将其理解为, creating a directory recursively

rm:rm [-fir]  file or directory   options and Parameters:-F: Is  force  means, ignore nonexistent files, do not appear warning message-I: interactive mode, Before the deletion will ask the user whether the action-r: hand-back Delete Ah! Most commonly used in directories are removed (this is a very dangerous option) example [[email protected] ~]# rm rice.php          #删除文件需要确认 [[email protected] ~]# rm -f rice.php       #强制删除文件不确认 [[email protected] ~]# rm -rfv ./rice       #强制删除当前的test目录, and displays the detailed procedure for deleting mv:mv [-fiu] source destination  options and Parameters:-f :force  Mandatory meaning, if the target file already exists, will not ask and directly overwrite-i&nbsp: If the target file   (destination)   already exists, will ask whether to overwrite-u : If the target file already exists and   source  newer, only upgrade   (update) Note: MV There is also a use of renaming, the most common day is also the most examples [[EMAIL PROTECTED] ~]# MV ABC  abc.php   #将abc移动成abc. php[[email protected] ~]$ mv /home/rice.txt / database      #将rice. txt moved to the database directory touch:-a : Revision only  access time-c  : Only the time of the file is modified, if the file does not exist the new text is not createdPiece-d : the date after which you want to revise it instead of the current date, you can also use the  --date= "date or Time"-M : Modify only  mtime-t : The time after which you want to revise it instead of the current time, in the format [YYMMDDHHMM] Example [[email protected] ~]# touch test.php                     #将test. php file time changed to, current time, file not exist [[ email protected] ~]# touch -c -t 05071803 test.php    # Change the archive time to, May 7 18:3 [[email protected] ~]# touch -r abc.php test.php          #将test. php file changed to root abc.php [[email protected] ~]# touch - d  "2 days ago"  test.php    #将test. PHP Date modified to 2 days ago

cat:cat [-abentv]  options and Parameters:-a : equivalent to-vet  integration options, Some special characters can be listed instead of blank-b : List line numbers, only for non-blank lines to do the line number display, blank lines do not mark the line number-e : The end of the break byte  $  display-n : Print the travel number, along with the blank line will also have line number, Unlike the  -b  options   (commonly used)-T&NBSP: The  [tab]  key is displayed in  ^I -v : lists some special characters that are not visible more:more   (one-page turn to view) Common shortcut keys: Blank key   (space): Represents a downward row enter        : Represents a downward row/ String         : Represents the keyword in this display, searching down the string for the word:f           &NBSP: Displays the file name immediately and the number of rows currently displayed q            &NBSP: Represents exit b  or  ctrl+b  : Represents a page back, but this action is only useful for files 

Less:less (page by page) Less and more difference: In more time, we have no way to turn front, can only look back, but if you use less, you can use [PageUp] [PageDown] The function of the key to go back to look at the file commonly used shortcut keys: Blank key: [PageDown]: Turn down a page [PageUp]: Flip a page/string: down to search the function of the string? String: Search for the function of the string N: Repeat the previous Search (with/or about!) N: Reverse the repetition of the previous search (with/or?)! Q: Leave less this program Head:head [-N number] file options and Parameters:-N: followed by numbers, indicating the meaning of a few lines (default is the first 10 rows) Tail:tail [-N number] file options and Parameters:-N: followed by number The word, which represents the meaning of a few lines (the default after 10 lines)-F: Indicates a continuous view of the subsequent files, to wait until the CTRL + C to end tail view (Tail–f is very useful when we look at some frequently updated logs, example: Tail-f/var/log/maillog)

2. Bash's work characteristics the command execution status return value and command line expansion are involved in the content and its sample demonstration.

Features in Bshell: Command completion Command History view command history: History-c: Empty command history-D: Delete command at specified location-w: Save command history to history file command alias alias cmdalias= ' command [options] [   Arguments] ' aliases defined in the shell are valid only for the current shell life cycle; The valid range of aliases is only the current shell process; command-line edit Ctrl + A: Skip to command line ctrl+e: Skip to command end Ctrl+u: Delete the cursor to the beginning of the command CTRL+K: Delete the cursor to the end of the command line

3. Use the command line expansion function to complete the following exercises:

(1), create/tmp directory: A_c, A_d, B_c, B_d

Mkdir-p/tmp/{a_c,a_d,b_c,b_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

├──tmp

├──usr

│└──local

│├──bin

│└──sbin

└──var

├──lock

├──log

└──run

Mkdir-p/mylinux/{bin,boot,dev,etc,lib,lib64,proc,sbin,sys,tmp,usr,var,lock,log,run}mkdir-p/mylinux/boot/ Grubmkdir-p/mylinux/etc/{rc.d,sysconfig}mkdir-p/mylinux/etc/rc.d/init.d/mkdir-p/mylinux/etc/rc.d/sysconfig/ Network-scriptsmkdir-p/mylinux/lib/modulesmkdir-p/mylinux/usr/local/{bin,sbin}

4, what is the metadata information of the file, what does it mean, how to view it? How to modify timestamp information for a file.

For:

Access: Last access time modify: Last Modified time change: state changed time (system maintained, cannot be arbitrarily modified) TOUCH-A: Update only access times (while updating the change to current time) touch- M: Update modify time only (update change to current time) Touch-c: Do not create a new file touch-t: Update the timestamp example with the specified time: touch-t [[CC]YY]MMDDHHMM[.SS] FileName

5, how to define the alias of a command, how to reference the execution result of another command in the command?

(1) [[Email protected] ~] alias dir= ' Ls-ar ' #设置别名可以是命令带参数 (2) You can define an environment variable, or write it as a shell script to invoke.

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.

find/var/-maxdepth 1-name "l*[0-9]*[a-z]"

7. Displays files or directories that start with any number in the/etc directory and end with a non-numeric number.

find/etc/-maxdepth 1-name "[0-9]*[!0-9]"

8, Show/etc directory, start with a non-letter, followed by a letter and any other arbitrary length of any character file or directory.

find/etc/-maxdepth 1-name "[0-9]*[a-z-a-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-2016-08-06-09-32-22.

Touch tfile ' date + '%y-%m-%d-%h-%m-%s '

10. Copy all the files or directories in the/etc directory to the/tmp/mytest1 directory that begin with P and do not end with a number.

ls/etc/| grep "^p[^0-9]*$" | Xargs-i Cp-r {}/tmp/mytest1

11. Copy all files or directories ending with. D in the/etc directory into the/tmp/mytest2 directory.

Find/etc-maxdepth 1-name "*.D" | Xargs Cp-r/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.

find/etc/-type f-name "[lmn]*conf" |xargs cp-rf/tmp/mytest3/

Linux Common management commands use