isIP('1.1.1.01') = true?

[mentalmap]

"1.1.1.01" is an invalid ip address.

[chriso]

Is it invalid? There was some discussion in #490.

[mentalmap]

For obvious reasons, it's invalid.

Just a Javascript sample:

var net = require('net');
var client = new net.Socket();

// 54.235.131.019 is ip address of api.ipify.org
client.connect(80, '54.235.131.019', function() {
    client.write('GET / HTTP/1.1\r\nHost: api.ipify.org\r\n\r\n');
});

client.on('data', function(data) {
    console.log('Received: ' + data);
    client.destroy();
});

client.on('close', function() {
    console.log('Connection closed');
});

If "54.235.131.019" is valid, then the program would get result. but not!

BTW, The program get success result in Mac, but not in Linux(eg: Centos 7).

[chriso]

Not saying that I disagree with you, but whether or not the node.js net module accepts leading zeroes says nothing about whether they're valid everywhere. I'll need a RFC reference before making any changes.

[chriso]

BTW, The program get success result in Mac, but not in Linux(eg: Centos 7).

So on Mac OS X you get the same result with leading zeroes?

[mentalmap]

On Mac OS X, IP with leading zeroes is ok.

[chriso]

More reading at:

• https://en.wikipedia.org/wiki/IPv4
• https://en.wikipedia.org/wiki/Dot-decimal_notation

[chriso]

ping on OS X interprets octets with leading zeroes as octal notation:

$ ping 8.8.8.010
PING 8.8.8.010 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: icmp_seq=0 ttl=47 time=53.670 ms
64 bytes from 8.8.8.8: icmp_seq=1 ttl=47 time=60.050 ms

[mentalmap]

PING is OK(Mac and Linux), but not in node client.

[mentalmap]

In WIKI：

But this also means addresses where an IP address component is written with a leading zero digit may be interpreted differently by different programs: some will ignore the leading zero, some will interpret the number as octal.

That results in inconsistent result.

[chriso]

Right, but leading zeroes are still technically valid in some cases. Whether or not <insert_tool_or_lib_here> supports them are outside the scope of this library.

[orekav]

Maybe it could be replaced by:
/(^\s*((([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))\s*$)/