hi guys

trying to understand what this line means

sed is a stream editor and i understand that, i have a file already selected
i want to edit so i use -e

sed -e

the next stesp is s/$*

s is a subsititute replacement

sed -e s/$*/[WORDS DELETED]/g

$ is in reference of the last line
/g makes it global so it would search everything

what does */[WORDS DELETED] do?

Hi,

sed -e s/$*/[WORDS DELETED]/g

The part between the first and second forward slash ($* in the example) is the string to look for. The part between the second and third forward slash ([WORDS DELETED] in the example) is what you want to change it into.

The $ is a refenrence to the end of the line, not the last line (it is not a line range). The example is rather useless because it will search for characters after the end of the line.

The -e option is used if you want to use multiple expressions in sed. Mostly used from within a script.

Example:

sed 's/This/That/g' => Change This into That anywhere on a line.

sed -e 's/Is/Was/g' -e 's/All/None/g' => Change Is in was _and_ All to None, anywhere in the line(s).

Also see:
man sed
http://sed.sourceforge.net/grabbag/tutorials/
http://www.grymoire.com/Unix/Sed.html

Hope this helps.

__________________

The dead stay dead and the living only wait to join them........

This is an extremely confusing and subtle question. It is very easy to get this wrong.

First the dollar sign works differently in sed depending on where it appears.

sed '$d' < /etc/passwd
will print the contents of /etc/passwd, all except the last line. That is an example of $ being used as a line number.

On the other hand:
echo box | sed 's/.*x$/something/'
echo boxes | sed 's/.*x$/something/'
shows the dollar sign anchoring an expression.

But to act as an anchor, the dollar sign must appear as the last character in the expression. Otherwise it becomes a regular character:
echo '$$$$$$$$' | sed 's/$*/something/'

Now in all of these examples, the sed command was enclosed in single quotes. That is not the case in the question. Thus the shell will see $* and probably replace it. Exactly what will happen depends on the shell and the context. I am using ksh:
set one
echo $*
echo one | sed s/$*/something/

The final command will print "something".