HI all,

How can i replace the nth line of a file with the value of a variable ?

which utility should i use?

Hi subwrc,

what is a "nth line".
Please give an example to us.

I guess he means n-th line (where n means whatever number).

A bit of quoting hell, but this works in bash:

n=2
VAR="a text variable"
sed $n's/^.*$/'"$VAR"'/' < $FILE

Sorry fla5do,as Ika said i mean the n-nth line where n=is a number

Thanks Chillies I 'm going to try it and repost

Or like this...

sed "${n}s/.*/${VAR}/" $FILE

I was worried that the .* could, in pathological circumstatnces, get expanded by the shell to a filename.

Now I'm confused:

$ n=2
$ VAR=a
$ mkdir -p 2s/.foo/a
$ touch 2s/.foo/a/bar
$ ls ${n}s/.*/${VAR}/
bar
$ ls "${n}s/.*/${VAR}/"
ls: 2s/.*/a/: No such file or directory

I suppose only variables are expanded in double quotes ...

Correct. For a simpler example try...

echo *
echo "*"