Example

     When building a sample program with /def=_USE_STD_STAT, you can
     observe the following:

     o  When the DECC$POSIX_STYLE_UID logical is enabled:

        -  For a system, that supports POSIX style identifiers:

           - getpwnam_r API reads information from the TCP/IP proxy
           database and fills UID and GID with values from the
           TCP/IP proxy database.

           - getgrgid_r API returns gr_name and gr_mem from
           the right's database associated with GID returned by
           getpwnam_r API.

        -  System with no support for POSIX style identifiers,
           getpwnam_r fills GID and UID with SYSGEN parameters as
           "DEFUID" and "DEFGID".

     o  When the DECC$POSIX_STYLE_UID logical is not defined:

        getpwnam function returns information about a user database
        entry for the specified name, which is specified in
        SYSUAF.DAT

       #include <unistd>  // getuid()
       #include <pwd>     // getpwuid_r()
       #include <grp>
       #include <errno.h>
       #include <stdio.h>
       #include <string.h>

       main()
       {

       struct passwd pwd2;
       const unsigned int PWD_BUFF_SIZE = 1024; 
       const unsigned int GRP_BUFF_SIZE = 1024;

       struct passwd *p_passwd;
       struct passwd *result;
       struct group *grpresult;
       struct group grp;
       char pwdBuffer[PWD_BUFF_SIZE],*name;
       char grpBuffer[GRP_BUFF_SIZE];
       char buf[PWD_BUFF_SIZE];

       gid_t gid;
       uid_t uid;

       int status;
       p_passwd = getpwnam("user1");
       uid=p_passwd->pw_uid;
       gid=p_passwd->pw_gid;

       printf("User id is %u\n", uid);
       printf("Group id is %u\n", gid);

       status = getpwnam_r("user1", &pwd2, pwdBuffer, PWD_BUFF_SIZE, &result);

       gid = pwd2.pw_gid;

       status = getgrgid_r(gid, &grp, grpBuffer, GRP_BUFF_SIZE, &grpresult);

       gid=grp.gr_gid; name=grp.gr_name;

       strcpy(name,grp.gr_name);

       printf("Group id is %u\n", gid);
       printf("Group name is %s\n", name);

       }

     Running the example program with /def=_USE_STD_STAT produces
     the following result:

     o  When the DECC$POSIX_STYLE_UID logical is NOT enabled, prints
        uid as 11010118 (result of 65536*168+ 70) and gid as 168
        with group name as RTL.

     o  When the DECC$POSIX_STYLE_UID logical is enabled and POSIX
        style identifiers are supported, prints uid as 70, gid as
        168 with group name as FOR_POSIX_TEST (retrieved from TCP/IP
        proxy database).

     o  When the DECC$POSIX_STYLE_UID logical is enabled, but POSIX
        style identifiers are not supported, prints uid as DEFUID,
        gid as DEFGID with group name as invalid buffer.