if_up

Ensure a TCP/IP interface is available

Note: If you aren't root, specify the full path: /usr/sbin/if_up.

Syntax:

if_up [-alp] [-m milliseconds] [-r retries] [-s seconds] interface...

Runs on:

QNX Neutrino

Options:

-a
Wait until all specified interfaces are configured. The default is to wait until a single interface is configured.
-l
(“el”) Wait for the network link to be marked as being up. This causes if_up to wait until the physical network link is up. This option may not be supported by some drivers.
-m milliseconds
Wait this number of milliseconds before rewalking the interface list. The default is 1000 ms.
-p
Wait only until the specified interfaces are present. The default is to wait until the interfaces are both present and configured. This is useful if you intend to configure the interface manually, after it's present (e.g., using the ifconfig utility).
-r retries
The number of times to walk the interface list. The default is 5.
-s seconds
Wait this number of seconds before rewalking the interface list. The default is 1.
interface
The name of the interface to wait on (e.g., en0, en1, …).

Description:

You can use this convenience utility while booting to ensure that a TCP/IP interface is available to those utilities that require one. It's primarily intended for use with the dhcp.client. When if_up is run in the foreground in a startup script, the script doesn't continue until the specified interfaces are marked as “UP” and have been assigned an IP address, or the utility has timed out.

If you specify both the -m and -s options, the one you specify last prevails.

Abilities:

The if_up utility may require the following abilities:

Use secpolmonitor to determine which abilities if_up is using on your specific system.

For more information on abilities, see procmgr_ability() in the C Library Reference.

Examples:

See dhcp.client.

Files:

libsocket.so
The if_up utility requires the libsocket.so shared library.
/usr/sbin/if_up
The if_up utility is located in the /usr/sbin/ directory, which isn't included in the default PATH of non-root users. If you aren't root, specify the full path.

Exit status:

0
Success.
>0
An error occurred.