samba - Dec 2002 - Need to know the code error returned by smbmount utility

I used the smbmount command in a system call in a C program, i.e.
{
    sprintf(req, "smbmount //NTMAX/SAMBA /usr/mf
-o                         
ip=192.168.2.17,username=Administrator,password=super");

   ret=system(req);
   printf("after mount: ret=%d err=%d\n",ret,errno);
}

I tried this program in different situations, when a firewall was
active, 
when the host was disconnected and when the remote directory was not 
sharable. Below is what I got.

2096: Connection to Davide2000 failed
SMB connection failed
after mount: ret=256 err=0

error connecting to 192.168.2.17:139 (No route to host)
2124: Connection to NTMAX failed
SMB connection failed
after mount: ret=256 err=0

2152: tree connect failed: ERRDOS - ERRnosuchshare (You specified an
invalid 
share name)
SMB connection failed
after mount: ret=256 err=0

It seems to me that I would have to parse the returned string to figure
out the error which seems to be the number before the colon.Is there any
other way?

Where can i find the list of code errors could be returned by smbmount
or other samba utilities? 

TIA.
-- 
Philippe Baronnet <philippe.baronnet@club-internet.fr>