Shell Programming and Scripting

Hi,
i need to make a script bash that takes in input three parameters: a text file that contains an old license, a file that contains a new license, and a directory that contains source files and i have to substitute to these file the old license with the new one.

So, i think tu use sed, in this way:

Code:

$old_license= 'cat old_license.txt'
$new_license= 'cat new_license.txt'

sed -i -e "s/$old_license/$new_license/g" $file

but i got this error "unescaped newline inside substitute pattern"..
How can i do to solve my problem?

thanks to all

Try
or better

Code:

old_license=$(cat old_license.txt)
new_license=$(cat new_license.txt)

sed -i -e "s/$old_license/$new_license/g" $file

If this doesn't work for you, run following in the shell: cat old_license.txt cat new_license.txt and copy the output from the shell and paste it here in codetags.

You cannot have an unescaped newline in sed replacement text ($new_license in your example). sed scripting uses the newline just like the shell does, to terminate a command. If you need a newline in the replacement text, you need to precede it with a backslash. Alternatively, if you're using gnu sed and do not care about portability to other sed implementations, you can replace a newline with a \n, in the replacement text (all posix-compliant seds allow this in the regular expression, but not in the replacement ... it is a gnu extension).

This approach is also vulnerable to sed metacharacters in both the regular expression and the replacement text. If old_license and new_license can contain characters that are special to sed, you need to rethink what you are doing. Perhaps use awk's string functions to accomplish the replacement without using regular expressions, or use perl, whose syntax supports quoting interpolated values in regular expressions.

Regards,
Alister