glibc/sysdeps/posix/ulimit.c

93 lines
2.4 KiB
C

/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdarg.h>
#include <sysdep.h>
#include <ulimit.h>
#include <unistd.h>
#include <limits.h>
#include <sys/resource.h>
/* Function depends on CMD:
1 = Return the limit on the size of a file, in units of 512 bytes.
2 = Set the limit on the size of a file to NEWLIMIT. Only the
super-user can increase the limit.
3 = illegal due to shared libraries; normally is
(Return the maximum possible address of the data segment.)
4 = Return the maximum number of files that the calling process
can open.
Returns -1 on errors. */
long int
__ulimit (int cmd, ...)
{
struct rlimit limit;
va_list va;
long int result = -1;
va_start (va, cmd);
switch (cmd)
{
case UL_GETFSIZE:
/* Get limit on file size. */
if (__getrlimit (RLIMIT_FSIZE, &limit) == 0)
/* Convert from bytes to 512 byte units. */
result = (limit.rlim_cur == RLIM_INFINITY
? LONG_MAX : limit.rlim_cur / 512);
break;
case UL_SETFSIZE:
/* Set limit on file size. */
{
long int newlimit = va_arg (va, long int);
long int newlen;
if ((rlim_t) newlimit > RLIM_INFINITY / 512)
{
limit.rlim_cur = RLIM_INFINITY;
limit.rlim_max = RLIM_INFINITY;
newlen = LONG_MAX;
}
else
{
limit.rlim_cur = newlimit * 512;
limit.rlim_max = newlimit * 512;
newlen = newlimit;
}
result = __setrlimit (RLIMIT_FSIZE, &limit);
if (result != -1)
result = newlen;
}
break;
case __UL_GETOPENMAX:
result = __sysconf (_SC_OPEN_MAX);
break;
default:
__set_errno (EINVAL);
}
va_end (va);
return result;
}
weak_alias (__ulimit, ulimit);