What these options exactly mean in ifup command in Linux?

Question

Please can someone explain to me more (maybe with examples ) about the following options in ifup command in Linux.

This is what I found on the internet, but with no more details about it :

• --force Force configuration or deconfiguration of the interface.
• --allow=CLASS Only allow interfaces listed in an allow-CLASS line in /etc/network/interfaces to be acted upon.
• -X PATTERN, --exclude=PATTERN Exclude interfaces from the list of interfaces to operate on by the PATTERN. PATTERN uses a usual shell glob syntax. If shell wildcards are not used, it must match the exact interface name. This option may be specified multiple times resulting in more than one pattern being excluded.
• -o OPTION=VALUE Set OPTION to VALUE as though it were in /etc/network/interfaces.
• -n, --no-act Don't configure any interfaces or run any "up" or "down" commands.
• --no-mappings Don't run any mappings. See interfaces for more information about the mapping feature.
• --no-scripts Don't run any scripts under /etc/network/if-*.d/
• -l, --list For ifquery, list all the interfaces which match the specified class. If no class specified, prints all the interfaces listed as auto.

I'm using Centos 6 and couldn't find the /etc/network/interfaces file, maybe because I'm using Network Manger and not static IP settings.