contrib/opie/libmissing/getutline.c

   1 /* getutline.c: A replacement for the getutline() function
   2
   3 %%% copyright-cmetz-96
   4 This software is Copyright 1996-2001 by Craig Metz, All Rights Reserved.
   5 The Inner Net License Version 3 applies to this software.
   6 You should have received a copy of the license with this software. If
   7 you didn't get a copy, you may request one from <license@inner.net>.
   8
   9         History:
  10
  11         Modified by cmetz for OPIE 2.32. Fixed check for fread() return
  12                 value.
  13         Modified by cmetz for OPIE 2.31. If the OS won't tell us where
  14                 _PATH_UTMP is, play the SVID game, then use
  15                 Autoconf-discovered values.
  16         Created by cmetz for OPIE 2.3.
  17 */
  18
  19 #include "opie_cfg.h"
  20 #include <stdio.h>
  21 #include <utmp.h>
  22 #include "opie.h"
  23
  24 static struct utmp u;
  25
  26 #ifndef _PATH_UTMP
  27 #ifdef UTMP_FILE
  28 #define _PATH_UTMP UTMP_FILE
  29 #else /* UTMP_FILE */
  30 #define _PATH_UTMP PATH_UTMP_AC
  31 #endif /* UTMP_FILE */
  32 #endif /* _PATH_UTMP */
  33
  34 struct utmp *getutline FUNCTION((utmp), struct utmp *utmp)
  35 {
  36   FILE *f;
  37   int i;
  38
  39   if (!(f = __opieopen(_PATH_UTMP, 0, 0644)))
  40     return 0;
  41
  42 #if HAVE_TTYSLOT
  43   if (i = ttyslot()) {
  44     if (fseek(f, i * sizeof(struct utmp), SEEK_SET) < 0)
  45       goto ret;
  46     if (fread(&u, sizeof(struct utmp), 1, f) != 1)
  47       goto ret;
  48     fclose(f);
  49     return &u;
  50   }
  51 #endif /* HAVE_TTYSLOT */
  52
  53   while(fread(&u, sizeof(struct utmp), 1, f) == 1) {
  54     if (!strncmp(utmp->ut_line, u.ut_line, sizeof(u.ut_line) - 1)) {
  55       fclose(f);
  56       return &u;
  57     }
  58   }
  59
  60 ret:
  61   fclose(f);
  62   return NULL;
  63 }