getpwnam() -error checking

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3 total messages Started by Ajay Kumar Gummadi Wed, 27 Mar 1996 08:55

#3157

Author: Ajay Kumar Gummadi
Date: Wed, 27 Mar 1996 08:55

16 lines
792 bytes

Hi all,

  The function getpwnam() takes the user-id as input argument and returns 
a pointer to a structure, that contains all the user information.

  If I give a wrong /non-existent user-id as input argument, how can I 
check the error condition that may arise, before, the system dumps core.

  Reply by email will be very helpful.

  Thanks.


bye
ajay

Re: getpwnam() -error checking

#3158

Author: Lawrence Kirby
Date: Wed, 27 Mar 1996 12:22

22 lines
1285 bytes

In article <Pine.SOL.3.91.960327025242.5526B-100000@ee.tamu.edu>
           ajay@ee.tamu.edu "Ajay Kumar Gummadi" writes:

>
>Hi all,
>
>  The function getpwnam() takes the user-id as input argument and returns 
>a pointer to a structure, that contains all the user information.

Or a null pointer on error.

>  If I give a wrong /non-existent user-id as input argument, how can I 
>check the error condition that may arise, before, the system dumps core.

Note that getpwnam() is not a part of the C language - it was inappropriate
to cross-post this to comp.lang.c.

-- 
-----------------------------------------
Lawrence Kirby | fred@genesis.demon.co.uk
Wilts, England | 70734.126@compuserve.com
-----------------------------------------

Re: getpwnam() -error checking

#3166

Author: Mark J. Bobak
Date: Thu, 04 Apr 1996 17:45

26 lines
1459 bytes

In article <Pine.SOL.3.91.960327025242.5526B-100000@ee.tamu.edu>,
Ajay Kumar Gummadi  <ajay@ee.tamu.edu> wrote:
>
>Hi all,
>
>  The function getpwnam() takes the user-id as input argument and returns 
>a pointer to a structure, that contains all the user information.
>
>  If I give a wrong /non-existent user-id as input argument, how can I 
>check the error condition that may arise, before, the system dumps core.
>
>  Reply by email will be very helpful.

getpwnam() will return a pointer to a struct passwd on success or a NULL
on failure.  So, just check to see if you were passed a NULL.  If you were,
then the user id probably doesn't exist.  (I say probably doesn't exist because
there may be other error conditions that would cause getpwnam() to return NULL.)

You'd be better off asking this in comp.unix.programmer.

-Mark
-- 
Mark J. Bobak, Application Developer
Advanced Vehicle & Computer Aided Engineering Systems Department
Process Leadership, Ford Motor Company
mbobak@ford.com

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