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/* Copyright (C) 1992, 1996, 1997, 2001, 2002, 2006
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
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <sys/resource.h>
/* Increment the scheduling priority of the calling process by INCR.
The superuser may use a negative INCR to decrement the priority. */
int
nice (int incr)
{
int save;
int prio;
int result;
/* -1 is a valid priority, so we use errno to check for an error. */
save = errno;
__set_errno (0);
prio = getpriority (PRIO_PROCESS, 0);
if (prio == -1)
{
if (errno != 0)
return -1;
else
__set_errno (save);
}
result = setpriority (PRIO_PROCESS, 0, prio + incr);
if (result == -1)
{
if (errno == EACCES)
errno = EPERM;
return -1;
}
return getpriority (PRIO_PROCESS, 0);
}
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