newlib/libc/unix/getlogin.c

   1 #ifndef _NO_GETLOGIN
   2
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <utmp.h>
   7 #include <fcntl.h>
   8 #include <_syslist.h>
   9
  10 char *
  11 getlogin ()
  12 {
  13   int utmp_fd;
  14   struct utmp utmp_buf;
  15   static char buf[10];
  16   extern char *ttyname ();
  17   char *tty;
  18
  19   if ((tty = ttyname (0)) == 0)
  20     return 0;
  21
  22   if ((utmp_fd = open (UTMP_FILE, O_RDONLY)) == -1)
  23     return 0;
  24
  25   if (!strncmp (tty, "/dev/", 5))
  26     tty += 5;
  27
  28   while (read (utmp_fd, &utmp_buf, sizeof (utmp_buf)) == sizeof (utmp_buf))
  29     {
  30       if (!strncmp (tty, utmp_buf.ut_line, sizeof (utmp_buf.ut_line))
  31           && utmp_buf.ut_type == USER_PROCESS)
  32         {
  33           close (utmp_fd);
  34           memset (buf, 0, sizeof (buf));
  35           strncpy (buf, utmp_buf.ut_user, sizeof (utmp_buf.ut_user));
  36           return buf;
  37         }
  38     }
  39
  40   close (utmp_fd);
  41   return 0;
  42 }
  43 #endif /* !_NO_GETLOGIN  */