How do i use basic level sed?

blackrhino

Sed commands on a file, run on the entire file by default , unlike ed for instance which works on just the current line by default.

Unlike the ed command, Sed does not edit the file you give it, the output has to be piped or redirected to a file.

I have a test file called data_file with contents

hamster, furry little creature, 2 hamster drive
donkey, back breaking helper, 8 donkey jacket road
horse,  top racer, 12 Horse throat Lane
badger,  night rider, 15 Badger Close 
cow,  love eating grass all day, 16 Moofield Aveune
sheep, can you take this coat off, 6 Wool road

Chain two sed commands together using semicolons, first change drive to gardens and second change Close to close.

$ sed 's/drive/gardens/; s/Close/close/' data_file 
hamster, furry little creature, 2 hamster gardens
donkey, back breaking helper, 8 donkey jacket road
horse,  top racer, 12 Horse throat Lane
badger,  night rider, 15 Badger close 
cow,  love eating grass all day, 16 Moofield Aveune
sheep, can you take this coat off, 6 Wool road

Another way to chain sed commands together with "-e" option of sed

$ sed -e 's/drive/gardens/' -e  's/Close/close/' data_file 
hamster, furry little creature, 2 hamster gardens
donkey, back breaking helper, 8 donkey jacket road
horse,  top racer, 12 Horse throat Lane
badger,  night rider, 15 Badger close 
cow,  love eating grass all day, 16 Moofield Aveune
sheep, can you take this coat off, 6 Wool road

You can add a number sed commands in a sed script and call it with the "-f" option.
sed -f scriptfile file

This is a useful sed command, "-n" do not print the output by default, but add "p" to the end of the command, this way you can see only the line that are changed.

$ sed -n -e 's/drive/gardens/p' data_file 
hamster, furry little creature, 2 hamster gardens