Dear Sirs,

I am using encryption of my C-Shell file through Vi editor's X option. After saving the C-Shell file and when I tried to execute C-Shell file, the linux system says "cannot execute binary file". I have already made necessary permissions and executable using
chmod u+x filename
for the C-Shell commands file.

Kindly help me to solve this problem. Is there any other way of encrypting a csh file?. If so, kindly let me know.

Regards,
Bhaskar Gopalan
E-Mail : bhaskar_gopalan@rediffmail.com

Well, if you encrypt your csh file, then first symbols are not #! - and so you have problems executing it.
What effect do you want to achieve? To make script unreadable? To make script unexecutable without password? How strong security do you want?

Generally, write a script that will decrypt and run its own tail after some comment, and prepend it to every encrypted script. But security will not be high.

Hello sir,

Even after I removed the #! option in the first line, the system says the problem namely "cannot execute binary file".

What I need in the encryption of the csh file is that the file should be unreadable alone with reasonable security.

Regards,
Bhaskar Gopalan

Hello sir,

Even after I removed the #! option in the first line, the system says the problem namely "cannot execute binary file".

What I need in the encryption of the csh file is that the file should be unreadable alone with reasonable security.

Regards,
Bhaskar Gopalan

You still do not have first line with #! and then valid interpreter name.
About what you want: first, if it is executable without password it is in most cases readable without password also (except for cases with powerful compilers+obfuscators, when you can get something in assembler). Also if you do not want to complicate things too much, you have to decrypt file somewhere, and in that case root can find that moment of time and read the scripts. You can go to http://www.datsi.fi.upm.es/~frosal/sources/ and take shc - shellscript compiler which does approximately what you want. Or you can modify it to request password from keyboard which will make it not so vulnerable.

Two things.

First: vim != vi
There are those who think the two are synonymous since vim comes installed in most distros. They aren't. Vim is "vi-improved". Vi (and ex) are intended to be very short and sweet and small (and fast). Vim is also intended to be small and fast (compared to other editors), but it has many things vi doesn't. The reason I say this is twofold:

1. Any newbies reading might become confused. That misconception will keep spreading.
2. Vi and ex are pretty much guaranteed to be available on every system (even the really stripped down, minimal ones). One day, sooner or later, you will find yourself trying to debug a problem on such a computer. You should know the abilities/limitations of vi.

This isn't a slam on vim or on vi. It is just a simple statement that will better the understanding of unixes among all of us.

Second: If you encrypt a file, you need to decrypt it to use it!
Linux does many things but it doesn't automatically decrypt shell scripts encrypted in vim. What you need is to write a shell script wrapper. This wrapper copies an encrypted wrapper. Then it will decrypt that file. To do this, you probably need to invoke vim as `ex' and you can use it as a script. The encryption should then be turned off (in the ex script). Then, the C-sh file should be executed. Afterward, it should be deleted.

Moved: This thread is more suitable in Linux - Software and has been moved accordingly to help your thread/question get the exposure it deserves.