Remove a line from a file

Shell Programming and Scripting
1

Hi ,guys. I have one question:

I want to write a script which removes a line with certain string from a file, for example

The name of the file is: "passwd", the contents of it is below:

*************************
...
brownj2:x:5000:
hynesp:x:5001:
leeb:x:5002
dioxna:x:5003
...

*************************
I want to remove the line with "brownj2" from the file.

Here is my code:
user="brownj2"
sed '/^user:/'d passwd

But, this does not work
Firstly, line with "brownj2" is not removed.
Secondly, I got all the contents in passwd shown up in the terminal, which is not what I want

Can anybody help me with this?

Thank you very much for your time in advance.

-Keyang

2 
sed "/$user/d" passwd > newpasswd && mv newpasswd passwd

or if your sed version supports the -i option (check your manpage):

sed -i "/$user/d" passwd

Regards

3

Hi, Franklin52:

Thank you very much for your reply, it works well!

-Keyang