sed command line editor "original"

sed command line Editor

SED is a non-interactive editor that processes object files by row, but does not modify the processing file itself, but instead reads the contents of the file row by line and saves the copy in a temporary buffer and processes it. Processing completes each row to print the row target content to the screen, deletes the cache content, and then reads the next line for processing. It is also important to note that, unlike grep, SED has an exit status of 0 regardless of whether the specified pattern is known (Linux usually represents true). The exit status of SED is not 0 unless there is a syntax error.

Double quotes are not used in single quotes

The original file is modified by default,

-N Silent Display

-I modify source file

-E Script

-f Specifies the file, which can have scripts

Sed-f/path/Script path file specified

-R Using Extended expressions

My raw material.

Var.txt

Yum_list

"About delimiter" and find content conflict can be used//, @ @ @, # # #

W command

"Delete Row management" D

Delete the second line sed ' 4d ' var.txt

Delete the second line to the last line sed ' 4,77d ' var.txt

Delete all rows containing root sed '/root/' d var.txt

Replace all root for LCLg for all sed ' s/root/lcl/g ' var.txt

Delete to the last line sed ' 4, $d ' Ll.txt

Delete + 4 line sed ' 5,+6d ' ll.txt

Remove sed '/^\//d ' fatab starting with a backslash

"Print line Management" p

Display the mode space content and display the conditions of the match bar two times sed '/^\//p ' fatab

Show only the contents of the Sed-n '/^\//p ' Fatab

"Line Append" a

Append new content to the qualifying line

sed  '/^\//a \ #hello  world '  fstab/dev/mapper/VolGroup-lv_root /                         ext4    defaults        1 1#hello  wordUUID=5dbd32f9-d400-4e24-a7fa-af5199575fe1 /boot                    ext4    defaults         1 2/dev/mapper/VolGroup-lv_home /home                    ext4     defaults        1 2#hello word/dev/mapper/ volgroup-lv_swap swap                   &nBsp; swap    defaults        0 0#hello  wordtmpfs                    /dev/shm                 tmpfs   defaults        0  0devpts                   /dev/pts                 devpts  gid=5,mode=620  0 0sysfs                    /sys                     sysfs    Defaults    &nbsP;   0 0 

I'm going to add two lines.

Sed '/^\//a \ #hello \ n Linux ' Fstrab

"Append line before match to" I

Use the same method as a

"Append the contents of a file below the line matched to," or to merge files

Under Line 5th, append the aaaa in the current path to sed ' 5r aaaaa ' Fastab

[[email protected] home]# sed  ' 4r aaaaaa '  fstab ## /etc/fstab#  created by anaconda on fri jun  5 18:17:35  2015423423894u234u2p93423423423523523523523## accessible filesystems, by reference,  are maintained under  '/dev/disk ' # see man pages fstab (5),  findfs (8),  mount (8)  and/or blkid (8)  for more info#/dev/mapper/volgroup-lv_root /                         ext4    defaults         1 1UUID=5dbd32f9-d400-4e24-a7fa-af5199575fe1 /boot                    ext4    defaults         1 2/dev/mapper/volgroup-lv_home /home                    ext4    defaults         1 2/dev/mapper/VolGroup-lv_swap swap                     swap     defaults        0 0tmpfs                    /dev/shm                 tmpfs    defaults        0 0devpts                   /dev/pts                 devpts  gid=5,mode=620  0 0sysfs                    /sys                      sysfs   defaults        0 0proc                     /proc                     proc    defaults        0 0

Append the contents of this file to line 5th through 7th.

Sed ' 5,7raaaaa ' fastabsed ' 5,7r aaaaa ' fastab This space is not all you can

W Save As

Matches the oot in Fastab and saves it to the Haha.txt file under the current path, which is also displayed by default

Sed '/oot/w haha.txt ' Fatab

Plus-n will not show the default

Sed-n '/oot/w haha ' fstab

"s Replace"

Replace the oot in Fstab with Oot.

Sed ' s/oot/oot/' fstab

I put fstab, each line first appeared slash/replace with #, note the escape character

Sed ' s/\//\#/' fstab

Slash/do processing only for the beginning of the line

Sed ' s/^\//\#/' fstrab

G Replace the found match with a/replace with #

Sed ' s/\//\#/g '

I ignore case, same as G usage

"Regular expression"

& references the entire string, no matter how long the preceding string

A regular expression that references a pattern, a back-reference

Source file Contents

Hello, like

Hi, My Love

Execute command sed ' s#l. E#&er#g ' Sed.txt

or perform sed ' s#\ (L. e\) #\1er#g ' Sed.txt

Hello, Likeer.

Hi, My Loveer

Match and modify the file

Encounter a match pattern, just modify one part of what to do

Can match to L. e expression, instead of L. EEr

Sed ' s#l\ (.. e\) #L \1er#g ' Sed.txt

Hello, Likeer.

Hi, My Loveer

-R Using Extended expressions

You delete the front space of the history

History | Sed ' s#[[:space:]]*# #g ' no matter how many spaces you have at the beginning of the line, you can erase them.

Show the first paragraph of the history command page

History | Sed ' s#^[[:space:]]*# #g ' | Cut-d '-f1

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sed command line editor "original"