newlib/winsup/cygwin/sysconf.cc

66 lines
1.5 KiB
C++

/* sysconf.cc
Copyright 1996, 1997, 1998 Cygnus Solutions.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <limits.h>
#include "fhandler.h"
#include "dtable.h"
#include "cygerrno.h"
/* sysconf: POSIX 4.8.1.1 */
/* Allows a portable app to determine quantities of resources or
presence of an option at execution time. */
long int
sysconf (int in)
{
switch (in)
{
case _SC_ARG_MAX:
/* FIXME: what's the right value? _POSIX_ARG_MAX is only 4K */
return 1048576;
case _SC_OPEN_MAX:
/* FIXME: this returns the current limit which can increase
if and when dtable::find_unused_handle is called. Perhaps
we should return NOFILE or OPEN_MAX instead? */
return fdtab.size;
case _SC_PAGESIZE:
{
SYSTEM_INFO b;
GetSystemInfo (&b);
return b.dwPageSize;
}
case _SC_CLK_TCK:
return CLOCKS_PER_SEC;
case _SC_JOB_CONTROL:
return _POSIX_JOB_CONTROL;
case _SC_CHILD_MAX:
return CHILD_MAX;
case _SC_NGROUPS_MAX:
return NGROUPS_MAX;
case _SC_SAVED_IDS:
return _POSIX_SAVED_IDS;
case _SC_VERSION:
return _POSIX_VERSION;
#if 0 /* FIXME -- unimplemented */
case _SC_TZNAME_MAX:
return _POSIX_TZNAME_MAX;
case _SC_STREAM_MAX:
return _POSIX_STREAM_MAX;
#endif
}
/* Invalid input or unimplemented sysconf name */
set_errno (EINVAL);
return -1;
}