inet_aton and struct issue

[David Bear]

I found this simple recipe for converting a dotted quad ip address to a
string of a long int.

struct.unpack(' L',socket.inet_ aton(ip))[0]

trouble is when I use this, I get

struct.error: unpack str size does not match format

I thought ip addresses were unsigned 32 bit integers.

Is there a better way to take a dotted quad and convert it to a string
representation of an long int?

--
David Bear
-- let me buy your intellectual property, I want to own your thoughts --

[Diez B. Roggisch]

Re: inet_aton and struct issue

David Bear schrieb:

I found this simple recipe for converting a dotted quad ip address to a
string of a long int.
>
struct.unpack(' L',socket.inet_ aton(ip))[0]
>
trouble is when I use this, I get
>
struct.error: unpack str size does not match format
>
I thought ip addresses were unsigned 32 bit integers.
>
Is there a better way to take a dotted quad and convert it to a string
representation of an long int?

Works for me:

>>import socket
>>import struct
>>ip = "127.0.0.1"
>>struct.unpack ('L',socket.ine t_aton(ip))[0]

2130706433L


Diez

[David Bear]

Re: inet_aton and struct issue

Diez B. Roggisch wrote:

David Bear schrieb:

>I found this simple recipe for converting a dotted quad ip address to a
>string of a long int.
>>
>struct.unpack( 'L',socket.inet _aton(ip))[0]
>>
>trouble is when I use this, I get
>>
>struct.error : unpack str size does not match format
>>
>I thought ip addresses were unsigned 32 bit integers.
>>
>Is there a better way to take a dotted quad and convert it to a string
>representati on of an long int?

>
Works for me:
>

>>import socket
>>import struct
>>ip = "127.0.0.1"
>>struct.unpack ('L',socket.ine t_aton(ip))[0]

2130706433L
>

I really wish it worked for me:

>>struct.unpack ('L', socket.inet_ato n('129.219.120. 129'))

Traceback (most recent call last):
File "<stdin>", line 1, in ?
struct.error: unpack str size does not match format

This is python packaged with Suse 9.3.

>>dir(struct)

['__doc__', '__file__', '__name__', 'calcsize', 'error', 'pack', 'unpack']

>>print struct.__file__

/usr/lib64/python2.4/lib-dynload/struct.so

could I have a broken python?

>
Diez

--
David Bear
-- let me buy your intellectual property, I want to own your thoughts --

[David Bear]

Re: inet_aton and struct issue

David Bear wrote:

Diez B. Roggisch wrote:
>

>David Bear schrieb:

>>I found this simple recipe for converting a dotted quad ip address to a
>>string of a long int.
>>>
>>struct.unpack ('L',socket.ine t_aton(ip))[0]
>>>
>>trouble is when I use this, I get
>>>
>>struct.erro r: unpack str size does not match format
>>>
>>I thought ip addresses were unsigned 32 bit integers.
>>>
>>Is there a better way to take a dotted quad and convert it to a string
>>representatio n of an long int?

>>
>Works for me:
>>

> >>import socket
> >>import struct
> >>ip = "127.0.0.1"
> >>struct.unpack ('L',socket.ine t_aton(ip))[0]

>2130706433L
>>

>
I really wish it worked for me:
>

>>>struct.unpac k('L', socket.inet_ato n('129.219.120. 129'))

Traceback (most recent call last):
File "<stdin>", line 1, in ?
struct.error: unpack str size does not match format
>
This is python packaged with Suse 9.3.

>>>dir(struct )

['__doc__', '__file__', '__name__', 'calcsize', 'error', 'pack', 'unpack']

>>>print struct.__file__

/usr/lib64/python2.4/lib-dynload/struct.so
>
could I have a broken python?
>

>>
>Diez

>

I played around with format size and here are some results. (they don't make
sense)

>>ip1 = '123.254.254.25 2'
>>import socket
>>import struct
>>ip1s = socket.inet_ato n(ip1)
>>struct.unpack ('L',ip1s)

Traceback (most recent call last):
File "<stdin>", line 1, in ?
struct.error: unpack str size does not match format

>>struct.unpack ('f',ip1s)

(-1.0592039033369 304e+37,)

>>struct.unpack ('I',ip1s)

(4244569723L,)

>>struct.unpack ('Q',ip1s)

Traceback (most recent call last):
File "<stdin>", line 1, in ?
struct.error: unpack str size does not match format

>>struct.unpack ('L',ip1s)

Traceback (most recent call last):
File "<stdin>", line 1, in ?
struct.error: unpack str size does not match format

>>struct.unpack ('i',ip1s)

(-50397573,)

>>struct.unpack ('I',ip1s)

(4244569723L,)

>>>

So, ip1s really should be a long unsigned int.. but it doesn't decode as
that. Is this the way to interpret this?

--
David Bear
-- let me buy your intellectual property, I want to own your thoughts --