Shell Programming and Scripting

This sed command actually do a display of the file contents till that line. But it does not physically remove those lines from the file. Is it that i have to redirect output from this sed command to another file ? Or this sed command does the deletion of those lines? I did the same way it was mentioned here.

Thanks

Well, as usually with *nix commands the output is, by default, redirected to the screen (stdout). Now, if you want you can redirect it to a file:

Code:

sed '......' infile > outfile

That's the safe way. You keep the original file intact and you can inspect the outfile to see if it is like required. All it takes when everything is ok is to cp that outfile onto the original file.

Now, some version of sed permits to make the changes "in place" but be warned: there is no way back.

Code:

sed -i  '......' infile

I would recommend to use the option -i with a suffix:

Code:

sed -i.bak '......' infile

A backup file infile.bak will be created.