[ih] 13 the unlucky number

Tue Aug 11 10:57:10 PDT 2020

I believe MacOS (I’m on Catalina, 10.15, but pretty sure previous versions are the same) is doing %I. The leading 0 is forcing octal. Removing the leading zero lets the OS see decimal. For instance:

patrick at TiggerBook-C-32 ~ % ping 10.010.010.10 
PING 10.010.010.10 (10.8.8.10): 56 data bytes

-- 
TTFN,
patrick

> On Aug 11, 2020, at 1:51 PM, Joseph Touch via Internet-history <internet-history at elists.isoc.org> wrote:
> 
> It seems like the input functions of the implementations vary. When using scanf:
> 
> 	%d, %x, %o 	= interpret the input as only decimal, hex, or octal (respectively)
> 
> 	%I			= interpret the input based on its format:
> 						0x… 	= hex
> 						0…		= octal
> 						(1-9)…	= decimal
> 						0b…	= binary (in some systems)
> 
> It looks like MacOS is using %d and linux/others are using %I
> 
> Joe
> 	
> 
>> On Aug 11, 2020, at 9:50 AM, Carsten Bormann via Internet-history <internet-history at elists.isoc.org> wrote:
>> 
>> On 2020-08-11, at 01:58, Alejandro Acosta via Internet-history <internet-history at elists.isoc.org> wrote:
>>> 
>>>     010.rrr.rrr.rrr   ARPANET       ARPANET [17,1,VGC]
>> 
>> Off-topic, but I can’t read this in any other way than as an octal number.
>> 
>> $ ping 010.010.010.010
>> PING 010.010.010.010 (8.8.8.8) 56(84) bytes of data.
>> 64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=6.35 ms
>> $ ping 134744072
>> PING 134744072 (8.8.8.8) 56(84) bytes of data.
>> 64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=6.31 ms
>> $ ping 01002004010
>> PING 01002004010 (8.8.8.8) 56(84) bytes of data.
>> 64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=6.31 ms
>> $ ping 0x8080808
>> PING 0x8080808 (8.8.8.8) 56(84) bytes of data.
>> 64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=6.30 ms
>> 
>> Does anyone remember how this misfeature crept into the C library?
>> (I seem to remember seeing it all the way back to 4.2BSD.  
>> It no longer works with macOS, but still does on the Linuxes I tried.)
>> 
>> Grüße, Carsten
>> 
>> -- 
>> Internet-history mailing list
>> Internet-history at elists.isoc.org
>> https://elists.isoc.org/mailman/listinfo/internet-history
> 
> -- 
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://elists.isoc.org/mailman/listinfo/internet-history