updating a single line by script

Shell Programming and Scripting
1

hi,
I'm trying to add a # to the beginning of the line where the a word is included.

and the i want to run the whole original script.

and if possible I would prefer that line would stay in the same order in the text file, the line which includes the word.

Thanks,

2

sed 's/.*word/#&/'

3

Thank you,

I am really new at shell scripting.

However I have a little problem when I do this.

Lets say that my original script is as follows;

#!/bin/ksh
echo "a"
echo "b"
echo "c"

and the update script;

#!/bin/ksh
sed 's/.*b/#&/' original.sh
./original.sh

the result i obtain is as follows;

#!/bin/ksh
echo "a"
#echo"b"
echo "c"

and the original.sh is not updated

how can i update original.sh or how can i see the output as;

a
c

4

If you only see the updated result on your screen (std out) then try this:

sed 's/.*b/#&/' original.sh > temprorary.sh
mv temprorary.sh original.sh
5

mv original.sh old.sh
sed 's/.*b/#&/' old.sh >original.sh
chmod 755 original.sh

6

Thank you so much..

7

You need the mode to make it actually executable, along with the #! first line.

8

I konw that one,
I added the mode to the script and right now it works perfectly...
Thanks again..

9

Otherwise, without the execute permission but with read permission you can

ksh original.sh

by the way if you put

#!/usr/bin/ksh

as a first line, it might be a good idea to name it

original.ksh

instead ...

10

Thank again,

What should i do if I want to to remove the #, I have tried coule of things on the sed you've told me, however it didnt work.

Now if I have sth like

echo "a"
#echo"b"
echo "c"

when I tried I ended up deleting everything until the word I've searched;

echo "a"
b"
echo "c"

but I want to have

echo "a"
echo"b"
echo "c"

11 
mv yourfile yourfile.old
sed 's/#\(.*\)/\1/' yourfile.old >yourfile
rm yourfile.old