SED

How to show only a given line or range of lines? sed -n '1p' file_name sed -n '1,5p' file_name sed -n '$p' file_name → prints all records

How to see all the users from India Country? sed -n '/India/p' file_name

How to use multiple expression in sed command? Example: If you wanna only see 2 and 5th line, -e this tells sed its a new expression sed -n -e '2p' -e '5p' file_name

How to see all the users from India and Germany? sed -n -e '/India/p' -e '/Germany/p' file_name

How to see next 4 lines from 2nd line? sed -n '2,+4p' file_name

How to see every 2nd line from first line? sed -n '1~2p' file_name

→ How to replace a word in a file and show?

s/ → means substitute

/g→ means global

sed 's/<string_to_change>/<new_string>/g' file_name

How to replace a word in a file and show except a given line or only in given line? sed '5 s/<string_to_change>/<new_string>/g' file_name

sed '5! s/<string_to_change>/<new_string>/g' file_name

How to replace a word and and edit in your file? sed -i 's/<string_to_change>/<new_string>/g' file_name

How to change salary or country of a user (Paul)? sed '/Paul/ s/25000/35000/g' file_name sed '/Paul/ s/India/US/g' file_name

How to delete a line? sed '1d' file_name (to delete first line) sed '1,2d' file_name sed '$d' file_name

How to delete user from India country? sed ‘/India/d’ file_name

How to delete empty line? sed '/^$/d' file_name

How to replace tab with space? sed 's/\t/ /g' file_name

How to copy output of sed command in separate file? sed -n ‘/India/ w new_file_name’ file_name

How to add new line after a given line no.? sed '5 a new_text' file_name

How to add new line after a given string, so it will add text after Paul? sed '/Paul/ a new_text' file_name

How to edit existing line instead of adding new line? sed '5 c new_text' file_name (it will add text at line 5) means it will delete old line and puts this

How to add new line before a given string, so it will add text before Paul? sed '/Paul/ i new_text' file_name

sed '1 i abc xyz' file this will insert new line abc xyz at line 1 and push content downwords

How to see the hidden characters? sed -n 'l' file_name

this is useful when, lets say you hvae a tab space after some word then this command will show something like word\t$

How to wrap your file content with given no. of characters? sed -n 'l 50' file_name

this will set max length for a line.. i.e 50 chars, after 50 chars it will split that line…

How to read content from a file and use in our command? sed '3 r externalfile' file_name

How to stop execution of sed command as soon as first occurance found? sed ‘/India/ q’ file_name sed ‘5 q’ file_name (stop execution at line 5)

q means quit

How to provide exit status for your sed command? sed ‘/India/ q 100’ file_name

How to execute external command line date in your expression? sed '2 e date' file_name

this will append the date command output in 2nd line

How to see the line number in file? sed '=' file_name

SED Regular Expressions ^ start of line $ end of line . single character [] match character set [^] exclusive Set

zero or more occurance

examples: sed -n '/^V/p' file_name -> this prints names starts with V

sed -n '/ia$/p' file_name → ends with

How to find a 5 letter name which start with S and end with a? sed -n '/^S...a$/p' names

How to find names start with V? sed -n '/^V/p' names

How to find names end with a? sed -n '/a$/p' names

How to use wild card? ls -ltr *.txt

How to see names start with only A and C? sed -n '/[AC]/p' names sed -n '/[AC]/p' names

How to see names start with only A to D? sed -n '/^[A-D]/p' names

POSIX Classes

/ResponseTime=[0-9]+ms/

/Endpoint=//

Example: sed -n ‘/[[:alpha:]]/p’ posix

[:alnum:] [:alpha:] [:digit:] [:blank:] [:lower:] [:upper:] [:punct:] [:space:]