On Tue, 2009-08-18 at 18:34 -0500, Tom Collins wrote:
> How often does the code actually reference the UID/GID? Could you
> have a function to look it up and cache it in a static once found?
>
> A quick check and it looks like it's only referenced when adding a
> user or updating the tcp.smtp.cdb file. There are a few other
> references, but the common things (like vchkpw and vdelivermail)
> don't appear to make use of it.
>
> Probably not a big deal to use getpwnam.
>
Not a big deal using getpwnam(). Also if you run nscd daemon,
password/group file lookups get cached
http://docs.sun.com/app/docs/doc/816-5166/nscd-1m?a=view
Also using getpwnam() function allows you to use hooks like NSS (Name
Service Switch) - http://en.wikipedia.org/wiki/Name_Service_Switch
In Unix-like operating systems, the Name Service Switch (NSS) allows
Unix configuration databases to be provided by different sources,
including local files (for
example: /etc/passwd, /etc/group, /etc/hosts), LDAP, and other sources.
In case it can be used, attaching a function GetVpopID() which I used
with vpopmail in my early days of using vpopmail. It uses static
variables to cache the uid/gid.
Regards Manvendra
http://www.indimail.org
!DSPAM:4a8b792832719326514358!
/*
* $Log: GetVpopID.c,v $
* Revision 1.3 2001-11-24 12:16:57+05:30 Cprogrammer
* version information added
*
* Revision 1.2 2001-11-20 10:53:16+05:30 Cprogrammer
* *** empty log message ***
*
* Revision 1.1 2001-10-24 18:15:00+05:30 Cprogrammer
* Initial revision
*
*/
#include "indimail.h"
#include <pwd.h>
#ifndef lint
static char sccsid[] = "$Id: GetVpopID.c,v 1.3 2001-11-24 12:16:57+05:30 Cprogrammer Stab mbhangui $";
#endif
int
GetVpopID(uid_t *uid, gid_t *gid)
{
struct passwd *pw;
static uid_t suid = -1;
static gid_t sgid = -1;
if(suid != -1 && sgid != -1)
{
*uid = suid;
*gid = sgid;
return(0);
}
if(!(pw = getpwnam(VPOPUSER)))
{
fprintf(stderr, "getpwnam failed for user %s\n", VPOPUSER);
return(-1);
}
*uid = suid = pw->pw_uid;
*gid = sgid = pw->pw_gid;
return(0);
}
void
getversion_GetVpopID_c()
{
printf("%s\n", sccsid);
printf("%s\n", sccsidh);
}
