sysdeps/unix/bsd/ulimit.c

   1 /* Copyright (C) 1991,1992,1994-1998,2001,2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <stdarg.h>
  21 #include <sysdep.h>
  22 #include <ulimit.h>
  23 #include <unistd.h>
  24 #include <sys/resource.h>
  25
  26
  27 extern int _etext;
  28
  29 /* Function depends on CMD:
  30    1 = Return the limit on the size of a file, in units of 512 bytes.
  31    2 = Set the limit on the size of a file to NEWLIMIT.  Only the
  32        super-user can increase the limit.
  33    3 = Return the maximum possible address of the data segment.
  34    4 = Return the maximum number of files that the calling process
  35        can open.
  36    Returns -1 on errors.  */
  37 long int
  38 ulimit (int cmd, ...)
  39 {
  40   struct rlimit limit;
  41   va_list va;
  42   long int result = -1;
  43
  44   va_start (va, cmd);
  45
  46   switch (cmd)
  47     {
  48     case UL_GETFSIZE:
  49       /* Get limit on file size.  */
  50       if (getrlimit (RLIMIT_FSIZE, &limit) == 0)
  51         /* Convert from bytes to 512 byte units.  */
  52         result = limit.rlim_cur / 512;
  53       break;
  54
  55     case UL_SETFSIZE:
  56       /* Set limit on file size.  */
  57       {
  58         long int newlimit = va_arg (va, long int);
  59
  60         if ((rlim_t) newlimit > RLIM_INFINITY / 512)
  61           {
  62             limit.rlim_cur = RLIM_INFINITY;
  63             limit.rlim_max = RLIM_INFINITY;
  64           }
  65         else
  66           {
  67             limit.rlim_cur = newlimit * 512;
  68             limit.rlim_max = newlimit * 512;
  69           }
  70
  71         result = setrlimit (RLIMIT_FSIZE, &limit);
  72       }
  73       break;
  74
  75     case __UL_GETMAXBRK:
  76       /* Get maximum address for `brk'.  */
  77       if (getrlimit (RLIMIT_DATA, &limit) == 0)
  78         result = ((long int) &_etext) + limit.rlim_cur;
  79       break;
  80
  81     case __UL_GETOPENMAX:
  82       result = sysconf (_SC_OPEN_MAX);
  83       break;
  84
  85     default:
  86       __set_errno (EINVAL);
  87     }
  88
  89   va_end (va);
  90
  91   return result;
  92 }