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Hello, |
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|
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On Mon, 20 Jul 2015, Meino.Cramer@×××.de wrote: |
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>on an embedded system I want to check, whether I have an eth0 "device" |
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>(ok, I know, it is not an device in the usual way...), when I attach |
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>an USB2Ethernet gadget via OTG-cable to it and whether all needed |
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>drivers are already there... |
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> |
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>How can I do that with at least impact at possible ? |
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|
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LC_ALL=C ip link show eth0 | grep -q 'state UP' |
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|
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if it's there, but no link, it's 'state DOWN' in the output. |
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Example output: |
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|
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# ip link show eth0 |
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2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UP qlen 1000 |
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link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff |
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# ip link show eth1 |
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3: eth1: <BROADCAST> mtu 1492 qdisc pfifo_fast state DOWN qlen 1000 |
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link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff |
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|
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and with the module for eth1 unloaded: |
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|
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# ip link show eth1 |
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# [nothing] |
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There's also other 'show' subcommands, most notably 'ip addr show', |
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with which you could check if you got an ip assigned. |
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Both commands show all devices if you omit the device argument (eth* |
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above). |
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|
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'ip' belongs to sys-apps/iproute2 and is the standard tool to set up |
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networking stuff (besides wifi) and thus already installed. |
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HTH, |
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-dnh |
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|
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-- |
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"There is hopeful symbolism in the fact that flags do not wave in a |
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vacuum." |
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-- Arthur C. Clarke |
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