Pointer of pointer with Ruby/DL

ruby-talk
1

I have the following C prototype:

int auth(char *user, char *passwd, char **msgp);

I pass user and passwd, and I get in response 0 or 1 for success or
failure and a message in *msgp.

How can i call this function from Ruby using Ruby/DL? So far I did the
following:

<code>
module Auth
  extend DL::Importable
  dlload "./auth.so"
  extern "int auth(char *, char *, char **)"
end

msgp = [0].pack('L').to_ptr
r = Tenant2Auth.public_tenant2_auth_pap_auth("coucou", "titi", msgp)
</code>

I get the correct result in 'r'. But how do I get access to the string
in *msgp?

I guess I don't yet have a good grasp on pointer dereferencing with
Ruby/DL.

Anyone?

Guillaume.

2

Try this:
msgp = DL.malloc(DL.sizeof('P'))
r = Tenant2Auth.public_tenant2_auth_pap_auth("coucou", "titi", msgp.ref)
puts msgp.to_s

Cheers,
Kent.

···

On Dec 8, 2004, at 10:13 AM, Guillaume Marcais wrote:

I have the following C prototype:

int auth(char *user, char *passwd, char **msgp);

I pass user and passwd, and I get in response 0 or 1 for success or
failure and a message in *msgp.

How can i call this function from Ruby using Ruby/DL? So far I did the
following:

<code>
module Auth
  extend DL::Importable
  dlload "./auth.so"
  extern "int auth(char *, char *, char **)"
end

msgp = [0].pack('L').to_ptr
r = Tenant2Auth.public_tenant2_auth_pap_auth("coucou", "titi", msgp)
</code>

I get the correct result in 'r'. But how do I get access to the string
in *msgp?

I guess I don't yet have a good grasp on pointer dereferencing with
Ruby/DL.

Anyone?

Guillaume.

3

Try this:
msgp = DL.malloc(DL.sizeof('P'))
r = Tenant2Auth.public_tenant2_auth_pap_auth("coucou", "titi", msgp.ref)
puts msgp.to_s

Works great, thanks.

Guillaume.

···

Le 8 déc. 04, à 12:25, Kent Sibilev a écrit :

Cheers,
Kent.
On Dec 8, 2004, at 10:13 AM, Guillaume Marcais wrote:

I have the following C prototype:

int auth(char *user, char *passwd, char **msgp);

I pass user and passwd, and I get in response 0 or 1 for success or
failure and a message in *msgp.

How can i call this function from Ruby using Ruby/DL? So far I did the
following:

<code>
module Auth
  extend DL::Importable
  dlload "./auth.so"
  extern "int auth(char *, char *, char **)"
end

msgp = [0].pack('L').to_ptr
r = Tenant2Auth.public_tenant2_auth_pap_auth("coucou", "titi", msgp)
</code>

I get the correct result in 'r'. But how do I get access to the string
in *msgp?

I guess I don't yet have a good grasp on pointer dereferencing with
Ruby/DL.

Anyone?

Guillaume.