Ifconfig
From Attie's Wiki
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== awk == | == awk == | ||
| − | + | This awk script will extract the configuration settings for an interface from the <code>/etc/network/interfaces</code> file. | |
| − | <source lang=" | + | |
| − | + | '''Contents of 'ifaceExtract':''' | |
| − | + | <source lang="text"> | |
| − | + | BEGIN { | |
| − | + | i = 0; | |
| − | + | got = 0; | |
| − | + | if (iface = "") iface="eth0"; | |
| − | + | addr = "192.168.1.1"; | |
| − | + | mask = "255.255.255.0"; | |
| − | + | } | |
| − | + | { | |
| − | + | if ($1 == "iface") { | |
| − | + | if ($2 == iface) { | |
| − | + | i=1; | |
| − | + | got=1; | |
| − | + | } else { | |
| − | + | i=0; | |
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
} | } | ||
} | } | ||
| − | + | if (i) { | |
| − | if (got) printf "ifconfig %s %s netmask %s\n", iface, addr, mask; | + | if ($1 == "address") addr = $2; |
| − | + | else if ($1 == "netmask") mask = $2; | |
| − | + | } | |
| − | + | } | |
| + | END { | ||
| + | if (got) printf "ifconfig %s %s netmask %s\n", iface, addr, mask; | ||
| + | else print "echo No interface " iface "..." | ||
| + | } | ||
</source> | </source> | ||
| − | Set the iface variable to the interface you wish to probe | + | |
| + | <source lang="bash"> | ||
| + | awk -v iface=eth2 -f ifaceExtract /etc/network/interfaces | ||
| + | </source> | ||
| + | |||
| + | Set the '<code>iface</code>' variable to the interface you wish to probe | ||
Expected output is as follows: | Expected output is as follows: | ||
| Line 39: | Line 44: | ||
echo No interface eth3... | echo No interface eth3... | ||
</pre> | </pre> | ||
| − | This means that it is possible to surround the awk script in backticks (`), and execute its output! | + | This means that it is possible to surround the awk script in backticks (``), and execute its output! |
Latest revision as of 16:26, 1 November 2011
[edit] awk
This awk script will extract the configuration settings for an interface from the /etc/network/interfaces file.
Contents of 'ifaceExtract':
BEGIN {
i = 0;
got = 0;
if (iface = "") iface="eth0";
addr = "192.168.1.1";
mask = "255.255.255.0";
}
{
if ($1 == "iface") {
if ($2 == iface) {
i=1;
got=1;
} else {
i=0;
}
}
if (i) {
if ($1 == "address") addr = $2;
else if ($1 == "netmask") mask = $2;
}
}
END {
if (got) printf "ifconfig %s %s netmask %s\n", iface, addr, mask;
else print "echo No interface " iface "..."
}awk -v iface=eth2 -f ifaceExtract /etc/network/interfaces
Set the 'iface' variable to the interface you wish to probe
Expected output is as follows:
ifconfig eth0 10.150.129.115 netmask 255.255.255.224
echo No interface eth3...
This means that it is possible to surround the awk script in backticks (``), and execute its output!
