AWK Command

SED Command in UNIX & Linux with example

Linux SED Command with example

SED Command :

  • SED is a powerful text stream editor. Can do insertion, deletion, search and replace (substitution).
  • SED command in UNIX supports regular expression which allows it perform complex pattern matching.

 AWK Command with Example

Syntax:

sed OPTIONS... [SCRIPT] [INPUTFILE...]

Example:

$cat > geekfile.txt
UNIX is great os. unix is opensource. unix is free os.
learn operating system.
unix linux which one you choose.
unix is easy to learn. Unix is a multiuser os. Learn unix .unix is a powerful.

Replacing or substituting string

LINUX SED COMMAND

LINUX SED COMMAND

By default sed replaces the first occurrence of pattern in each line and it won’t affect the 2nd and 3rd

Here ‘s’ is the substitution variable and ‘/’ are delimiters. The ‘unix’ is the search pattern and ‘linux’ is the replacement string.


Replacing the nth occurrence of a pattern in a line

LINUX SED COMMAND

LINUX SED COMMAND

The above command will replace the second occurrence in each line.


Replacing all the occurrence of the pattern in a line

Use /g (global) with sed command.


Replacing from nth occurrence to all occurrences in a line

LINUX SED COMMAND

LINUX SED COMMAND


Parenthesize first character of each word:

This sed command prints the first character of every word in parenthesis.


Replacing string on a specific line number

It will replace the occurrence at third line.


Duplicating the replaced line with /p flag

 /p print flag prints the replaced line twice on the terminal. If a line does not have the search pattern and is not replaced, then the /p prints that line only once.


Printing only the replaced lines 

Use the -n option along with the /p print flag to display only the replaced lines. Here the -n option suppresses the duplicate rows generated by the /p flag and prints the replaced lines only one time.


Replacing string on a range of lines

You can specify a range of line numbers to the sed command for replacing a string.

Learn about  AWK Command with Example.

One Reply to “SED Command in UNIX & Linux with example”

Leave a Reply