Shell-05 sed

Shell-05

sed command

Linux text processing Three Musketeers sed statement (line editing - flow editor stream editor)

As a line editor to edit the text, in units

Note: sed to edit the file, but do not change the original file;

Sed works:

         In sed which will provide an address space, will appear in the linux memory in a model space PATTERN SPACE, read a line

 

 

Develop a text file, a text file in order to read the contents of each line, to read the pattern space (PATTERN SPACE), text matching (regular expression) in the pattern space, the contents of the match modify ( replace , delete, print, edit, save)

Sed usage:

sed [option] …{script-only-if-no-other-script} [input-file]

sed [parameters] ... "sed own independent use format statement" [Text File]

Common options:

                          -r specify extended regular expressions

                                   Match IP address

                  　　     1. All of \ Do not

                               2. | or

-n refused default output

         But -n '1,2p' 99cfb.sh

-e     script for while if

         for i in {1..9};do echo “$i” sleep 1;done

-f script file specified

-L length specified text wrap

-i directly modify the contents of the file (do not use)

Sed address delimitation way of command

1. Direct matching value

However -n '5,7p' 99cfb.sh

1. digit for (number) to specify an increment step d ~

sed -n '1 ~ 3 / j / @ / p 99cfb.sh

1. $ Specified Gyoo

Sed -n '10, $ p 'file

                                   Sed -n '\ fd \, $ p' ----- file to match the last line from fd

              

 

1. 0, addr --- addr can be a digital / $ / regular expression
2. Sed -n ‘0,/k\{5,\}/p’ abc
3. Sed -n ‘/\(as\)\+/,/\(ds,\)\+/p’ abc
4. addr,+N

Addr line to the match, the lines addr N

Sed -n ‘/fd/,+5p’ abc

1. addr,-N

sed -n ‘1,~3p’ abc

Common commands:

                  p print print the default display on the screen, used in conjunction with -n recommended

                  c Replace the line sed "/ aaa / c \ A" file name

                  d delete sed "/ aaa / d" to delete the file name to match the line

                                   sed "1,3d" file name

                  n N Read / pattern matching is added to the contents of the next line in the line to manipulate

                  w Save the file contents to a new file

                  * S * replaces the default text contents of the first replacement pattern matching to the space

                                   All g global / global

                                  

                                   Syntax: intermediate s / pattern / string / replace any --- slash why a special character

                                    \ 1 \ 2 \ 3 ... and the regular expression is the same packet to achieve reverse application

                                                     Designate a replacement to modify a match

                           - fourth row if the third for replacing

                        Fourth row if the third and for replacing the stored 99xfb.sed.sh

                  i add content matching row line

                          sed “/for/i abc ” filename

                  Add the contents of a matching line in the next line

                          sed “/for/a abc ” filename

　　  

 

   Grip "testbash" / etc / passwd | Sed "s # ^ test. * # & Is # g"

 

 

E.g. s ###, s @@@, s %%%

sed “s/k/K/gw  /root/aabbcc” abc

sed of advanced applications             

D hold space- occupy space

                 

random number

                  RANDOM range 0-32767

                  A=$[$RANDOM%100+1]

         Exercise:

 

 

1. cat /boot/grub/grub.conf        sed  ‘s/^[[:space:]]\+//g’ /boot/grub/grub.conf
2. cat /etc/fstab               sed ‘s/^#[[:space:]]\+//’ /etc/fstab
3.  echo “/var/log/message | ”sed  ‘s/[^/]\+$//’
4. echo "/var/log/message" | sed  's#^/.*/##'
5. 

    

Remove the file path dirname path portion ----

Remove the file path of the basename file portions ----

 

Endless loop

while true;do

              Loop

done

break- break out of the loop

continue ---- out of this cycle

After prolonged sleep ---- how long to continue the cycle

until

       And while the use of the same

       Difference: only when the judgment condition is false, will enter the loop

Exercise 2:

 

 

#! / bin / bash 

CAT << EOF 

         menu

 ============================ " the CPU) display cpu information " " Mem) displays memory information " " disk) disk information displays " " the quit) to exit the " 
============================ 
EOF the while to true ; do 
       the Read - the p- " Please enter the required view: " info echo "" IF [the -z $ info ]; the then echo " Please enter a correct parameters !! " echo "For example: the CPU Mem the Quit Disk "

   

   

   

   



 

 
 

        

       

               

               

        #       exit 1

       fi

       if [ $info = "cpu" ];then

              cat /proc/cpuinfo

       elif [ $info = "mem" ];then

              free -m

       elif [ $info = "disk" ];then

              fdisk -l

       elif [ $info = "quit" ];then

              echo "已退出" 

              Exit   0 

       the else 

              echo  " input information is incorrect " 

              echo  " Please enter a valid argument! ! " 

             Echo  " For example: the CPU Mem Disk the Quit " 

              Exit 2 

       Fi 

DONE

 

 

progress bar

 

 

Vim .vimrc

Some of the default parameter editing vim

 

 

Cloud Desktop

Role: to assign a PC client from the cloud, so that customers work in the cloud;

1. Safety
2. Convenience

[In vim, representative of the current line cursor ".": "., $ S / ^ / # / ----- from the cursor to the beginning of the current line end of the line is replaced by #"]

1 to 3, 1,4,7,11 step ----

/ Pattern1 /, / pattern2 ---- from pattern matching to the line, the pattern matching to the line 1 2

Digital, + N

/pattern1/,+N------".,+3s/^#// "at the beginning of the line to the last three rows displaced from the cursor into the air current