sed command in Linux with Examples

The sed command is a stream editor for filtering and transforming text. In this tutorial, How to sed command in Linux with Examples.

The sed command-Line in Linux, which stands for “stream editor,” is a powerful text processing tool used for performing various text manipulations and transformations. It reads input line by line, applies specified operations, and outputs the result. Here are a few examples of how to use the sed command line:


sed [OPTION]... {script-only-if-no-other-script} [input-file]...

On the man page, the describes it

  • sed – modifies lines from the specified File parameter according to an edit script and writes them to standard output.
  • man sed – More details information about the sed command.
sed command in Linux with Examples

The sed command in Linux with Examples

For example, the file sed_test.txt as below

[huupv@DevopsRoles vagrant]$ cat sed_test.txt                                                                                                                                  
# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help

driftfile /var/lib/ntp/ntp.drift

# Enable this if you want statistics to be logged.
#statsdir /var/log/ntpstats/

statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable

# Specify one or more NTP servers.

# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See for
# more information.
pool iburst
pool iburst
pool iburst
pool iburst

Append line

$ sed '/^pool 3/ a server' sed_test.txt

Insert line

It will be added lines before the matching line.

$ sed '/^pool 3/i server' sed_test.txt

Delete line

used d to delete matching lines. \s is escaped for regular expressions.

$ sed ' /^pool\s[0-9]\.ubuntu/d' sed_test.txt

How to write multi-line

There are two ways, use {} or other files.

Use {}

$ sed ' {
 /^pool 0/i server
 } ' ./sed_test.txt

create a ntp.sed file and read with the -f option.

The content ntp.sed file.

/^pool 0/ i server prefer

Explain the above line.

/^$/d - Delete blank lines.
/^\s*#/d - Delete the line following # after any space including 0 (Delete comment line of #)

As a result

$ sed -f ntp.sed sed_test.txt

The backup file before changing the original file has been modified.

$ sed -i.bak -f ntp.sed ntp.conf

Print specific lines from a file

sed -n '2,5p' input_file

Delete lines matching a pattern

sed '/pattern/d' input_file

Append text after a specific line

sed '/pattern/a\new_line' input_file


sed Linux is a simple command in Linux. It uses the number of lines of files. These are just a few examples of how to use the sed command in Linux.

The sed command offers a wide range of text manipulation capabilities, including search and replace, insertions, deletions, and more. Thank you for reading the DevopsRoles page!

About HuuPV

My name is Huu. I love technology, especially Devops Skill such as Docker, vagrant, git, and so forth. I like open-sources, so I created to share the knowledge I have acquired. My Job: IT system administrator. Hobbies: summoners war game, gossip.
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