Linux Blog next week

Linux Second week blog
1.LinuxWhat are the file management class commands on, their common usage methods, and their associated example demos.

CP, MV, RM

1. Copy command: CP

CP [Option] ... [-T] SRC ( source ) DEST ( purpose )

dest, dest

           dest is the file that will src content covered to Span style= "FONT-SIZE:12PX;" >dest at this point it is proposed as CP -i options.

if DEST is a directory, Create a new file with the same name as the original file under DEST and populate the contents of SRC with in DEST )

Example: cp/etc/fstab/tmp/out.tmp (out.tmp for file)

Cp/etc/fstab/tmp/out (out for directory)

CP [Option] ... SRC(original file)... ( multiple files) directory(new directory) (which directory is copied to )

if src is a multiple file,directory must be present and directory, and other cases are wrong.

cp src DEST src is the directory:

Use the option at this time: -R (Recursive recursion )

if dest does not exist create the specified directory, copy SRC all directories in the directory to DEST in

if dest exist:

if dest is the file, then the error

if dest is a directory, it is copied to this directory

Common options:

- I.: Interactive

- R: recursively copy a directory and all its internal content

-A : Archive , equivalent -dr--preserv=all ( that is, preserve the properties of the source file or directory, including the owner, the owning group, permissions, and time)

-D:--no-dereference--preserv=links ( If the original file is a link, keep the original link format)

--preserv=[attr_list] ( reserved property)

mode: Permissions

Ownership: belong to the group of main genera

timestamp : Time Stamp

Links: links

xattr : Special Properties

Context: Context

All : All

-P =--preserve=mode, ownership, timestamp

- v Show more information

- T The target can be placed on the front when copying

- F--force Force replication ( Dangerous)

such as: cp/etc/apache2/tmp/apache2 (/etc/apache2,/tmp/apache2 as directory,)

cp-p/var/tmp/a.txt./temp/( reserved property)

2. Move File command: MV

MV [Option] ... [_t] SOURCE DEST to move the original file to the target file, which is renamed

mv {Option] ... SOURCE ... Directory to move source files to the destination file directory

MV [Option] ...-tdirectory SOURCE will be DIRECTORY as a moving target

Option

- I. Interactive , Prompt Action

- F forcing

such as: MV Test.log Test1.txt (renamed to test.txt)

MV test1.txttemp/( move to temp directory)

3. Delete command:RM

RM [OPTION] ... FILE ...

Common options:

- I.: Interactive

- F : Force Delete

- R: Recursive

rm-f A.log ( forcibly delete files)

rm-r tmp/( Delete tmp directory and its subdirectories and files)

2.bashthe command execution status return value and command-line expansion are involved in the work feature and its example demonstration.

Bash There are two kinds of command execution result states: Success / failed , Bash Use special variables $? to save the execution status result of the most recent command. 0 for success,1-255 represents various failures.

Bash the command line expansion: with {} means that you can host a comma-delimited list and expand it to multiple paths

such as: /tmp/{a,b}=/tmp/a,/tmp/b

/TMP/{A,B}/C=/TMP/A/C,/TMP/B/C

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

(1) , creating / tmp under the directory: A_c, A_d, B_c, B_d

Mkdir/tmp/{a,b}{_c,_d}

(2) , creating /tmp/mylinux under the directory:

mylinux/

650) this.width=650; "src=" Http://s4.51cto.com/wyfs02/M02/88/02/wKioL1fnuqGAydlyAAA0YpzxD-Y814.png "title=" QQ picture 20160925195151.png "alt=" Wkiol1fnuqgaydlyaaa0ypzxd-y814.png "/>

Mkdir-p

/tmp/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}

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

metadata contains information such as permissions, size, owner, group, and modification time of the file, available ls-l command to view. Use the Touch command to modify the timestamp information. Example:touch-t [yyyymmddhhmm] FILE

5. How do I define an alias for a command, and how do I refer to the execution result of another command in a command?

Use alias define individual names, alias aliasname = Command + option

To use a pipe to reference another command to execute the result , as ps-ef |grep httpd

6.Show/ varall the directories under theLA file or directory that begins with a lowercase letter ending with at least one digit (which can have other characters) appear in the middle.

ls/var/l*[[:d Igit:]]*[[:lower:]]

7.Show/ etcdirectory, a file or directory that begins with any number and ends in a non-numeric number.

ls/etc/[[:d igit:]]*[^[:d igit:]]

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

ls/etc/[^[:alpha:]][[:alpha:]]*

9.in the/ tmpdirectory under Create toTfileThe file, followed by the current date and time, has a filename such as:tfile-2016-08-06-09-32-22.

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

.Copy/ etcall the directories under thePA file or directory that ends in a non-numeric/tmp/mytest1the directory.

cp/etc/p*[^[:d igit:]]/tmp/mytest1/

One by one .Copy/ etcall the directories under the. Dend of file or directory to/tmp/mytest2the directory.

Cp-r/etc/*.d/tmp/mytest2

.Copy/etc/all the directories under theLormorNbegins with the. confend of file to/tmp/mytest3the directory.

cp/etc/[lmn]*.conf/tmp/mytest3/

Linux Blog next week