Hi,

I have 2 sets of text files. I need to take a field from a certain line in set 1 and put it in the same place in set b. The line appears once per file, in different places but is a set format and has the unique word "ANTENNA" in it and is always 81 characters long. Example from set a:

" 0.0000 0.0000 0.0000 ANTENNA: DELTA H/E/N"
Example from set b
" 0.2160 0.0000 0.0000 ANTENNA: DELTA H/E/N"

The bold bit is the field I'm trying to change and will be a random float in both sets.

I've been trying to do it like this:

#!/bin/ksh

old_line=`grep ANTENNA ./file1.txt`
new_line=`grep ANTENNA ./file2.txt`

sed "s/${old_line}/${new_line}/" file1.txt >tmp2 #substitute old line with new line in file 1 and output to tmp2

But this doesn't work, probably because I have forward slashes in my grep lines which sed interprets as some sort of regexp. How can I escape these when they are embedded in a variable? Am I quoting incorectly? Or is there a much better way?

Jon

sed "s\/${old_line}\/${new_line}\/" f

use escape sequence "\" and then try.

This results in the error:

sed: -e expression #1, char 81: unknown option to `s'

Much appreciated.

But if you have # in the lines you will get the same problem. Does sed not have a quotemeta function/option you can use for more general purposes and not have to worry about the specific delimiter in the search expression?

not that I'm aware of......