OpenSSL as a CA without touching the certs/crl/index/etc environment

I think I have the right OpenSSL command to sign a certificate but I've gotten stuck and the tutorials I've found use a different argument format (I'm using OpenSSL 0.9.8o 01 Jun 2010).

openssl ca -cert cert.pem -keyfile key.pem

(Private key is not encryped and CSR is on stdin.)

It gives this error

Using configuration from /usr/lib/ssl/openssl.cnf./demoCA/index.txt: No such file or directoryunable to open './demoCA/index.txt'

Looking at that configuration file:

[ ca ]default_ca = CA_default    # The default ca section[ CA_default ]dir      = ./demoCA        # Where everything is keptcerts    = $dir/certs      # Where the issued certs are keppcrl_dir  = $dir/crl        # Where the issued crl are keptdatabase = $dir/index.txt  # database index file.

I don't have any of this set up. I don't want to set any of this up.

Is it strictly nessecary, or is there a "don't bother" option?

I tried creating empty directories and files but I've got in a tangle. What I really want is for a command like the above to work, with the output on stdout, without touching anything on the filesystem.