Splitting a pointer

Posted on 2000-02-27
Medium Priority
Last Modified: 2010-04-15
What am I doing wrong here?  I am trying to split this pointer into two vars,

Can anyone help?

char *tdom, *tuser;
if ((tdom = strchr(p->pop_parm[1], 47)))
*tdom = '\0';
memcpy(tuser, p->pop_parm[1], sizeof(p->pop_parm[1]));
tuser[strlen(tuser) - strlen(tdom) - 1] = '\0';
(void)strncpy(p->domain, tdom, sizeof(p->domain) - 1);
p->domain[sizeof(p->domain)-1] = '\0';
(void)strncpy(p->user, tuser, sizeof(p->user));
p->user[sizeof(p->user)-1] = '\0';
pop_msg(p, POP_SUCCESS, "User: %s %d %d, Domain: %s %d %d",  p->user, sizeof(p->pop_parm[1]), sizeof(p->user), p->domain, sizeof(tdom), sizeof(p->domain));

Question by:Nitro187
  • 2
  • 2

Accepted Solution

Andrei Rodionov earned 300 total points
ID: 2563819
Hello Nitro187!

I think your problem consists in using pointer that is NOT initialized. Look,
you declare tuser and it points to... nothing! It looks like an auto variable therefore it contains garbage until you assign a reasonable value. So you'll get an access violation in

memcpy(tuser, p->pop_parm[1], sizeof(p->pop_parm[1]));

Besides, tdom = strchr(p->pop_parm[1], 47) can return NULL and your assignment *tdom = '\0'; can fail too...

There are some incomprehensibilities and I need more information about p pointer.



Author Comment

ID: 2566881
Hey,  ok, here is the struct, which P comes from:

typedef struct  {
int                 debug;
int                 xmitting;
int                 stats;
int                 dirty;
int                 kerberos;
int                 server_mode;
char            *   myname;
char            *   myhost;
char            *   client;
char            *   ipaddr;
unsigned short      ipport;
char                user[MAXUSERNAMELEN];
char                domain[MAXDOMAINLEN];
state               CurrentState;
int                 msgs_deleted;
int                 last_msg;
long                bytes_deleted;
char                drop_name[MAXDROPLEN];
char                temp_drop[MAXDROPLEN]
long                drop_size;
long                spool_end;
FILE            *   drop;              
FILE            *   input;
FILE            *   output;
FILE            *   trace;
FILE            *   hold;
char            *   pop_parm[MAXPARMCOUNT];
int                 parm_count;
char            *   bulldir;
} POP;

Any more ideas?

Expert Comment

by:Andrei Rodionov
ID: 2567608
Other code (from (void)strncpy(p->domain,... ) looks like correct. Once more, your problem is in tuser pointer.

What does it point to? I think it's NOT initialized!..


Author Comment

ID: 2571297
Ahh,  I had a tuser, and a ttuser,  I used the wrong one to init.  Thanks.. :P

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