2019 Nian 7 Yue 17 Wednesday Lesson
2.7 directory management commands
1 , Touch command to create a blank file or set file time
如：touch haha.txt
touch -d "19:00" modify file access and to modify the time
-a modification time reading -m modification modified -d The first two are modified
2, mkdir command creates a directory
If you want to create a directory iterative relationship to add parameters -p
Such as: mkdir -pa / B / C / D / E / F / G
3, cp command to copy a file or directory
To add parameters to copy the directory -r
如：cp -r Music/ haha
4, mv command cut and renaming files or directories
Operating under the same directory for renaming
5, rm command to delete a file or directory
Parameters -f forcibly remove (do not ask)
-r When you delete a directory to add
6, dd command to copy data or converted in accordance with the specified size and number of blocks
Parameters if input file file source
of outout file output file
count block
bs size
如：dd if=xiao.cfg of=da.cfg bs=20 count=1
To xiao.cfg take 2OK , take a secondary output to da.cfg
7, file command to view the file types
In linux everything is a file, the file directory is also included, so the file can also view the catalog file type.
2.8 packaged compression and search command
1 , tar commands for file compression or decompression package
Common parameters: 1 , -czvf
c create a compressed file
the gzip = Z ≠ ZIP or j = bz2
v display compression process
f the compressed file name
Such as: tar -czvf archive name .tar.gz source file
2, -xzvf
x Extract the files
Such as: tar-xzvf archive name .tar.gz
2 , grep command to perform keyword searches, and display the results
Such as: grep keyword source file
To display the number of rows can be added parameter -n
Such as: grep -n keyword source file
3 , the Find command to find files
Such as: Find / -name fstab
"/" Refers to the root directory, comprehensive search
" -Name " to match the file name
fstab as keywords
If no search results, there is no return value
Parameters -prune (ignoring a directory) must -path used simultaneously
如：find / -path /root -prune -name fstab
Chapter pipe symbol, redirection and environment variable
3.1 Input and output redirection
The command written to the output file as: LS -l> haha
Output redirection
> Clear write
>> additional writing
2> given written emptied
>> 2 additional write error
&> Whether or not an error, all output is redirected
Input redirection
<File import
As: WC -l <Anaconda-import the file into the ks.cfg command
3.2 Pipe command character
| Pipe character input before the output command to be processed later command
Such as: command A | B transmits commands command input to the command information A B
ls | wc -l the number of files in the directory Statistics
ps aux | grep ssh ssh statistical information on the process of
3.3 command line wildcard
* Can match or null character
? Only match one character
[] Matches the specific characters, separated by commas, such as: [1,3,5], or [1-9] , [AZ]
3.4 commonly used escape
1 , "" in order to avoid errors caused by the space program, selecting "" into a whole.
如：echo “hello word!”
2 , \ the operator later transformed into a pure character
Such as: PRICE =. 5
echo “Price is \$$PRICE”
The resulting output is: Price IS $ 5
3 , 'global escape, the' inside all operators characters transformed into pure
4 , `` content within backticks as a command