getting users' tty # into a C program

[John Mount]

>/ hpcupt1:comp.lang.c / davek at lakesys.UUCP (Dave Kraft) /  3:15 pm  Mar  5, 1989 /
>In article <9794 at smoke.BRL.MIL>, gwyn at smoke.BRL.MIL (Doug Gwyn ) writes:
>> In article <441 at lakesys.UUCP> davek at lakesys.UUCP (Dave Kraft) writes:
>> >I am writing a C program that need a user's tty number (i.e. tty3A).  Is there
>> >any internal/external function that can accomplish this?
>> 
>> Most UNIX systems have a ttyname() library function for doing this.
>> It doesn't work perfectly...
>
>
>Here's what I tried:
>
>main()
>{
>	char *name;
>
>	*name=ttyname();
>	printf("%s\n", *name);
>}
>
>(Plus I grepped around in all of the include files for ttyname, and I couldn't
>find it)  Is there anything I'm doing wrong in the above program?? 
>Thanks in advance.
>Dave
>
Read up!  ttyname needs a file descriptor as an argument and you shouldn't
be dereferencing name when you use it.  The following works on an Hp9000/360
running HPUX6.02:

#include <stdio.h>
extern char *ttyname();
main()
{
       char *name;

       name=ttyname(0);
       printf("%s\n", name);
       return(0);
}


John