Shell Programming and Scripting

hi


i have one file where i want to substitute only first instance of
swap
with swap1
i want to replcae only first instance of swap in my script

i know we can do this with awk. but i need to do this with sed only

i tried follwoing code
sed 's/swap/swap1' filename

but here all swap will get replaced with swap1

i want to replace only one and first instance of swap

plz guide me

Thank You
Best Regards,
Swapneel

This sounds like homework. Why not do it in awk?

You have syntax problem here ..
sed 's/swap/swap1' filename

Change as

sed 's/swap/swap1/' filename

hi,
see i m able to use sed command. i dont have any sytex errores. might be while typing here i missed out something.

see i m using sed command but i want to replace only first /or nth instance in file. i dont want replace all instances .

i repeat only first instance.

And guys thisis not home work. plz reply with solutions.

thanks
Swapneel

sed -e '1,/pattern/s/pattern/REPLACEMENT/' <INPUTFILE

dont ask me why it works...cause that will sound like homework....just figure it out :-)
regards

hi JunkYardWars

sed -e '1,/pattern/s/pattern/REPLACEMENT/' <INPUTFILE

it doesnot work. it will replace all instances of specified pattern.
i want to replace only first instance not the all


anyway thanks for your time.

Regards
swapneel

Code:

sed -e 's/pattern/REPLACEMENT/1' <INPUTFILE