get the status of the child process

i want to get the status of child process (when execvp is failed) in the father process so im useing the next code: (im programming on linux)

Code:

---

pid=fork();
if(pid==0)
{
if(execvp(com[0],com)==-1)
exit(-1);
}
else
{
waitpid(pid,&status,0);
}

---

but the value of status is stay a junk number.
can someone help me in this problem ?
thanks !

If you set status to 0 before calling waitpid() does it still contain 0 afterwards?
--
Mats

Quote:

---

Originally Posted by mystic-d

Code:

---

if(execvp(com[0],com)==-1)
exit(-1);
wait();

---

---

your child is getting exit as soon as it spawns a new process using execvp( )..
and parent gets the same with signal, the process spawned by execvp( ) is still running..
and is in zombie state..

try the 'wait();' and see it must be stopped till the execvp process returns..

Quote:

---

Originally Posted by gibsosmat

your child is getting exit as soon as it spawns a new process using execvp( )..
and parent gets the same with signal, the process spawned by execvp( ) is still running..
and is in zombie state..

try the 'wait();' and see it must be stopped till the execvp process returns..

---

What? You can't do wait() after exit() - because you never get there.

--
Mats

Quote:

---

Originally Posted by matsp

What? You can't do wait() after exit() - because you never get there.

--
Mats

---

its the else case not inside the if( )..
so that the child will wait for execvp( )
I think his problem being invalid pid provided to waitpid( )..
if we put wait( ); there it will wait till the execvp is done well..

if you just want to see what the status of the execvp( ) from parent process I think this is not what he should do..

i was set status to be zero before the "waitpid" and afterwards its have the value: "65280".

(but i want to get "-1"..)

Code:

---

#include <unistd.h>
#include <signal.h>
...
pid=fork();
if(pid==0)
{
    if(execvp(com[0],com)==-1)
        {
            printf("execvp failed\n");
            pause();
          exit(-1);
        }
}
else
{
    waitpid(pid,&status,0);
    printf("Status: &#37;d\n",status);
    kill(pid, SIGINIT);
}

---

try this..

If you look at the manual page, there are a bunch of macros which extract the true exit status of the child process from some other information which is all encoded into the same integer.

> afterwards its have the value: "65280".
Which is FF00 in hex, so your -1 is in there somewhere - see the macros!

i tryed all the macros and cant get it work...
any help will be aperciated...
thanks !

Tried how?
Show us what you did.