# Adding # before a line using csh

**URL:** <https://community.unix.com/t/adding-before-a-line-using-csh/316611>\
**Category:** Shell Programming and Scripting\
**Created:** [September 13, 2012, 4:07am UTC](https://community.unix.com/t/adding-before-a-line-using-csh/316611 "2012-09-13T04:07:54Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![vdhingra123](https://community.unix.com/letter_avatar/vdhingra123/32/5_5575768a8748004e209b776fc1b2916d.png) [@vdhingra123](https://community.unix.com/u/vdhingra123)\
**Post date:** [September 13, 2012, 4:07am UTC](https://community.unix.com/t/adding-before-a-line-using-csh/316611/1 "2012-09-13T04:07:54Z")

</div>

Hi,

I want to grep a word say "fan" from a file and redirect those lines in a file with "#" before them.

eg

all

```auto
fan is on
i am you
you are me
i am on fan

```

Expected o/p  
#fan is on  
#i am on fan

---

<div class="post-metadata">

**Author:** ![elixir\_sinari](https://community.unix.com/user_avatar/community.unix.com/elixir_sinari/32/2563_2.png) [@elixir\_sinari](https://community.unix.com/u/elixir_sinari)\
**Post date:** [September 13, 2012, 4:20am UTC](https://community.unix.com/t/adding-before-a-line-using-csh/316611/2 "2012-09-13T04:20:14Z")

</div>

```nohighlight
sed -n '/fan/s/^/#/p' origfile > newfile

```

---

<div class="post-metadata">

**Author:** ![pamu](https://community.unix.com/letter_avatar/pamu/32/5_5575768a8748004e209b776fc1b2916d.png) [@pamu](https://community.unix.com/u/pamu)\
**Post date:** [September 13, 2012, 4:48am UTC](https://community.unix.com/t/adding-before-a-line-using-csh/316611/3 "2012-09-13T04:48:52Z")

</div>

With awk...

```nohighlight
awk '/fan/{$0="#"$0;print}' file

```