Text Tool Three musketeers: SED

Text Tool Three musketeers: SED
SDE is a stream editor that processes a single line of content at a time. When processing, stores the currently processed rows in a temporary buffer, called the pattern space
Usage:
sed [options] [Add your own language] [file to process]
Options:
-N does not output the contents of the mode to the screen
# sed-n "10p" F2 only prints out line 10th matches to the row other does not show
Ten Uuid=07a475f4-3d7a-4b27-9ec9-500bc8a19c4d/boot
-e Multi-point editing
-F Read Edit script in specified file
-R supports the use of extended regular expressions
-I in situ edit

Script:
Address command

Address delimitation:
(1) Not to address: The full text of the processing
(2) Single address:
# The specified row
/mode/each row to which the pattern can be matched
(3) Address range
#,#
#,+#
/pat1/,/pat2/
#,/pat1/
(4) ~: Step forward
Odd lines
2~2 even rows

SED edit command
D Delete a row that matches the pattern space
Sed "10d" F2 delete the 10th line of F2 not directly delete the 10th line of the file
P Display the contents of the mode space
Sed "10p" F2 display line 10th 10th line of F2
Sed-n "10p" F2 only show line 10th print again

A \text append text at the back of the line; Support for multiline append using \ n
Sed "10a\===" F2 to the end of line 10th print = = =
Sed "a\===" F2 at the end of all lines print = = =

I \text inserting text in front of the line; Support for multi-row insertion using \ n
Sed "/uuid/i\===" F2 shown in front of the UUID =====

C \text-line or multiline text
Sed "/uuid/c\++++++++" F2 replace the rows that match the UUID to +++++++

W/path/to/somefile save pattern matching rows to the specified file
Sed "/uuid/w f3" F2 the rows to which the UUID matches are saved to F3


R/path/from/somefile reads the text from the specified file to the line in the pattern space
Sed "/uuid/r/etc/issue" F2 print the contents of the/etc/issue behind the UUID

= Print line numbers for lines in pattern space
Sed "/uuid/=" F2 the line in front of the UUID

！ Matching row-fetching anti-processing in pattern space
Sed "/uuid/!=" F2 except that the UUID line does not print the others are printed again

s///find replacement, support the use of other separators, [email protected]@@,s###
Sed "/uuid/s/xfs/chen/" F2 the line searching for the UUID in the F2 file to replace XFS with Chen

Replace tag
G in-line global substitution
P shows the row that replaced the successful
W/path/to/somefile save a successful row to a file

Display columns:
Sed ' 2p '/etc/passwd show/etc/passwd on line 2nd other also show

Sed–n ' 2p '/etc/passwd only shows/etc/passwd on line 2nd other not shown

Sed–n ' 1,4p '/etc/passwd show/etc/passwd 1~4 Line

Sed–n '/root/p '/etc/passwd search for root line other not shown

Sed–n ' 2,/root/p '/etc/passwd start searching for root line from line 2nd

Sed-n '/^$/= ' file displays empty line line numbers

Sed–n–e '/^$/p ' –e '/^$/= ' file

Sed '/root/a\superman '/etc/passwd after line

Sed '/root/i\superman '/etc/passwd before line

Sed '/root/c\superman '/etc/passwd instead of line

Sed '/^$/d ' file

Sed ' 1,10d ' file

nl/etc/passwd| Sed ' 2,5d '

nl/etc/passwd| Sed ' 2a tea '

Sed ' s/test/mytest/g ' example

Sed–n ' s/root/&superman/p '/etc/passwd after the word

Sed–n ' s/root/superman&/p '/etc/passwd words before

Sed-e ' s/dog/cat/'-e ' s/hi/lo/' pets

Sed–i.bak ' s/dog/cat/g ' pets

Practice
1. Delete all whitespace characters from the beginning of lines in the/etc/grub2.conf file that begin with whitespace
Sed ' s/^[[:space:]]\+//'/etc/grub2.cfg


2. Delete all # and white space characters at the beginning of the line beginning with #, followed by at least one white-space character, in the/etc/fstab file
1. Sed "s/^#[[:space:]]\+//"/etc/fstab

3. Add # At the beginning of each line of/root/install.log
Sed ' s/.*/#&/'/etc/passwd
Sed ' s/^/#/'/etc/passwd

4. Add # to the beginning of the line in the/etc/fstab file that does not begin with #
Sed '/^#/!s/.*/#&/' f2

5, processing/etc/fstab path, use sed command to take out its directory name and base name
echo "/etc/fstab" | Sed-r ' [Email protected]^ (/?. *)/[^/]+/[email Protected]\[email protected] '
echo "/etc/fstab" | Sed-r ' [email protected]^/?. */([^/]+/?) @\[email protected] '
6. Use SED to remove the IPv4 address of the ifconfig command
Ifconfig | Sed-n "2p" | Tr-s ' # ' | cut-d#-F3


SED: Advanced editing commands
H: Overwrite the contents of the pattern space in the hold space
H: Append the contents of the pattern space to the hold space
G: Remove data from hold space to pattern space
G: Append content from hold space to mode space
x: Swap the content in the pattern space with the content in the hold space
N: Reads the next line of the matched row to overwrite the pattern space
N: Append the next line of matching rows to the mode space
D: Delete rows in the pattern space
D: Delete all rows in multi-line mode space

Display columns:
Sed-n ' N;p ' FILE
Sed ' 1! G;h;$!d ' FILE
Sed ' $! n;$! D ' FILE
Sed ' $!d ' FILE
Sed ' G ' FILE
Sed ' g ' FILE
Sed '/^$/d; G ' FILE
Sed ' n;d ' FILE
Sed-n ' 1! g;h; $p ' FILE

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Text Tool Three musketeers: SED