contrib/opie/libmissing/pututline.c

   1 /* pututline.c: A replacement for the pututline() 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, use Autoconf-discovered values.
  15         Created by cmetz for OPIE 2.3.
  16 */
  17
  18 #include "opie_cfg.h"
  19 #include <stdio.h>
  20 #include <utmp.h>
  21 #include "opie.h"
  22
  23 #ifndef _PATH_UTMP
  24 #define _PATH_UTMP      PATH_UTMP_AC
  25 #endif /* _PATH_UTMP */
  26
  27 void pututline FUNCTION((utmp), struct utmp *utmp)
  28 {
  29   FILE *f;
  30   struct utmp u;
  31   int i;
  32
  33   if (!(f = __opieopen(_PATH_UTMP, 1, 0644)))
  34     return;
  35
  36 #if HAVE_TTYSLOT
  37   if (i = ttyslot()) {
  38     if (fseek(f, i * sizeof(struct utmp), SEEK_SET) < 0)
  39       goto ret;
  40     fwrite(utmp, sizeof(struct utmp), 1, f);
  41     goto ret;
  42   }
  43 #endif /* HAVE_TTYSLOT */
  44
  45   while(fread(&u, sizeof(struct utmp), 1, f) == 1) {
  46     if (!strncmp(utmp->ut_line, u.ut_line, sizeof(u.ut_line) - 1)) {
  47       if ((i = ftell(f)) < 0)
  48         goto ret;
  49       if (fseek(f, i - sizeof(struct utmp), SEEK_SET) < 0)
  50         goto ret;
  51       fwrite(utmp, sizeof(struct utmp), 1, f);
  52       goto ret;
  53     }
  54   }
  55
  56   fclose(f);
  57
  58   if (!(f = __opieopen(_PATH_UTMP, 2, 0644)))
  59     return;
  60   fwrite(utmp, sizeof(struct utmp), 1, f);
  61
  62 ret:
  63   fclose(f);
  64 }