SED - Basics

 

• Comment :  #

• Escape sequence :  \  (backward slash)

• Find and replace string in a file

• sed  ‘s/find_string/replace_string/g’ filename.c > outputfilename.c

• To make the backup of  file, use –i options

• sed  -i.bak ‘s/find/replace/g’ filename.c

• it makes the changes in filename.c but keeps the backup of that file in filename.c.bak

• It can also do all the operation via single command line also instead of file operation.

• Datafile  = echo   ‘$1’  |  sed ‘s/ zled/Zled/’

• Instead of using –i".bak”, use mv command

• Sed “pattern” $filename > temp

• mv temp $filename

• Script 

• List of commands

• Printing – p

• Deleting – d

• Substitution – s

• Range of selected line – comma

• Multiple edits – e

• Reading from file – r

• Writing to file – w

• Appending – a

• Inserting – i

• Changing – c

• Next – n

• Transform - y

• Quit – q

• Holding and getting – H & g

• Holding and exchange – h & x