Shell Programming and Scripting

I run my script which i wrote which has the job of inputing a line of text into a certain place in a file. When i run the script i get an error which relates to one line of code as shown below:

sed -n '$count p' $2 | cpio -o >> tempfile

The error i keep getting from this line is this:

sed: -e expression #1, char 3: Extra characters after command
1 block
sed: -e expression #1, char 3: Extra characters after command
1 block

and so on as long as it loops. Anyway i don't know why this is happenning and the file that i am inputing into tempfile contains a brunch of stuff that looks like this:

^@^@^@^@^@^@Çq^@^@^@^@^@^@^@^@^@^@^A^@^@^@^@^@^@^@^K^@^@^@^@^@TRAILER!!!^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@Çq^@^@^@^@^@^@^@^@^@^@^A^@^@^@^@^@^@^@^K^@^@^@^@^@TRAILER!!!^@



Why is this being output to the file and is their anyway to fix my orignal problem?

use double-quotes

That looks a little like untranslated EBCDIC text. Anyway, instead of sed which doesn't seem to like the data, try dd which is meant for playing with stuff like this.
dd will replace cpio and sed. dd will also translate EBCDIC to ASCII if you want.

man dd

I had it in double qoutes but in despair took them off. Cheers on the dd I'll have a look at it and see if it helps.

I've looked at dd and I don't know if it will work with what I am trying to do. From what i gather dd seems very good at copying with control on blocks. But i need to input a line in a particlar place in a file. The place is to do with line number. So i have loop like so:

while [ "$linenum" -gt 0 ]
do
sed -n ' "$count" p ' $2 | cpio -o >> tempfile

if [ "$linenum" -eq "$reqline" ]
then
echo $1 >> tempfile
fi
reqline=<various calc's>
count=`expr "$count" + 1`
linenum=`expr "$linenum" - 1`
done

I don't think dd will work in this context (I may be wrong ) as it won't let me specfic the line number. It will only let me skip a number of blocks and do things like that. Anyway my knowledge of dd is not complete so I may be wrong.

once again - use double-quotes:

Code:

sed -n "${count}p" myFile

You where right it works when I use the line :
sed -n "$count p" $2 >> tempfile

but not when i use:
sed -n '$count p' $2 >> tempfile


Yet at the command promt if I use say somthing like
sed -n '3 p' $2 >> tempfile
it works fine. Anyway thanks