Re^5: Need help with (un)pack templates

It's pretty well spelled out in the pack documentation. C for unsigned char (byte), n for unsigned 16-bit short in network order, N for 32-bit long in network order, a for "arbitrary binary data".

Don't be confused by the 32-bit CCCC's, since an IP address is 4 8-bit numbers, not a 32-bit number.

Comment on Re^5: Need help with (un)pack templates

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Re^6: Need help with (un)pack templates by ikegami (Patriarch) on Dec 20, 2009 at 17:25 UTC
Don't be confused by the 32-bit CCCC's, since an IP address is 4 8-bit numbers, not a 32-bit number. It's actually 32 opaque bits. The dotted form is just a representation. The separation into bytes in completely arbitrary. But if you're going to display in that form, it might be useful to extract the IP as 4 bytes.	[reply]
Re^6: Need help with (un)pack templates by keszler (Priest) on Dec 20, 2009 at 15:06 UTC
an IP address is 4 8-bit numbers, not a 32-bit number `s/is/is normally represented as/;` `$ host perlmonks.org perlmonks.org has address 66.39.54.27 $ perl -le 'print ((66 * 256*3)+(39 256*2)+(54 256)+27);' 1109866011 $ perl -le 'print unpack('N',(gethostbyname("perlmonks.org"))[4]);' 1109866011` [download] Many web browsers accept the decimal value of the IP address: http://1109866011/	[reply] [d/l] [select]
Re^7: Need help with (un)pack templates by gmargo (Hermit) on Dec 20, 2009 at 17:08 UTC
s/is normally represented as/is encoded in an IP header as/; # :-)	[reply]
Re^6: Need help with (un)pack templates by Subop (Acolyte) on Dec 20, 2009 at 15:47 UTC
Now it's making more sense... Thanks for the help, gmargo!	[reply]


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