Shell Programming and Scripting

Hi,

I searched the forum for this but couldn't find the answer. Basically I have a line of code I want to insert into a file using sed. The line of code is basically something like "address=1.1.1.1" where 1.1.1.1 is an IP Address that will vary depending on what the user enters. I'll just refer to it here as $address.

I did find something about append or insert with sed using this line:

sed '1a\
your text goes here' file_name > new_filename

How would this line look if I have a variable in the line? Any ideas? Thanks!

Elt

first of all where do you want to insert the text? append to the end of the file or insert it in the first line?

the code that you are trying would insert the text after the first line.

You can't put a variable inside a single-quotes string. So break the single-quoted string into two single-quoted strings and put the variable between them. For an example see our FAQ article on this subject.

Hey thanks guys. Actually what I was trying to do is have a script insert a line into a file with address=[some ip address] where the ip is something that the user inputs. It's supposed to be appended to a line which happens to be line 77. What I did was split my sed call into 2 so the first time it appends the address= and then the next one it appends the ip address which can vary. I was surprised that sed needs to be on different lines though, kinda interesting. Anyways I got it, but can someone link me to the FAQ for future problems. Thanks!

Elt

Code:

sed '77{p;s/.*/Your_String/;}' input_file