Shell Programming and Scripting

I'm trying to write a simple script that replaces a string. The script works for uninterrupted strings, but as soon as sed encounters a space it stops reading the new string. I've tried double quotations in sed and backslashes before the $, however these don't work. Below is the script. Any help would be greatly appreciated. Thanks.

#!/bin/tcsh
set stringOld=$1
shift
set stringNew=$1
shift
#
#Replaces stringOld with stringNew inside fileName
foreach file ($*)
mv $file $file.bak
sed s/$stringOld/$stringNew/g $file.bak > $file
if ( { cmp $file $file.bak } )then
echo \*\*$file has not changed
rm $file.bak
endif

end

try this:

Code:

sed 's/$stringOld/$stringNew/g' $file.bak > $file

While single quotations are the standard when using sed, they don't work in this case as $ needs to be treated as a special character.

could you post ur sample input and expected output

Say I have a file called hello.txt. Inside the file is the sentence "Hi. How are you?". I want to be able to replace any string in the sentence. If I try to replace "Hi" with "Hey you", I would write:

programName "Hi" "Hey you" hello.txt

After this I would expect to open the hello.txt and see the sentence

"Hey you. How are you?"

Instead, the sentence reads

"Hey. How are you?"

Not tested: try this or you could also find an ariticle in the FAQ section

Code:

sed "'s/'$stringOld'/'$stringNew'/g'" $file.bak > $file

Code:

>cat hi
hi how are you

Code:

old=hi
new='hey you'

Code:

sed "s/$old/$new/g" hi
hey you how are you