If --config file is the only option to the openvpn command, the --config can be removed, and the command can be given as openvpn file

Note that configuration files can be nested to a reasonable depth. Double quotation or single quotation characters ("", '') can be used to enclose single parameters containing whitespace, and "#" or ";" characters in the first column can be used to denote comments.

Note that OpenVPN 2.0 and higher performs backslash-based shell escaping for characters not in single quotations, so the following mappings should be observed:

\\       Maps to a single backslash character (\).
\"       Pass a literal doublequote character ("), don't
         interpret it as enclosing a parameter.
\[SPACE] Pass a literal space or tab character, don't
         interpret it as a parameter delimiter.

For example on Windows, use double backslashes to represent pathnames:

secret "c:\\OpenVPN\\secret.key"

For examples of configuration files, see http://openvpn.net/examples.html

Пример конфигурационного файла

#
# Sample OpenVPN configuration file for
# using a pre-shared static key.
#
# '#' or ';' могут быть использованы для разделения комментариев

# Использование tun device.
dev tun

# Удаленная точка 
remote mypeer.mydomain

# 10.1.0.1 - local VPN endpoint
# 10.1.0.2 - remote VPN endpoint
ifconfig 10.1.0.1 10.1.0.2

# pre-shared static key
secret static.key