view toys/nice.c @ 649:2364ace48ab1

Bugfix from Avery Pennarun: getpriority() uses a different range than nice(), so follow thenice man page and zero errno then check it if nice returns -1.
author Rob Landley <>
date Thu, 16 Aug 2012 22:24:30 -0500
parents b51faa4fe8e6
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/* vi: set sw=4 ts=4:
 * nice.c - Run a program at a different niceness level.
 * Copyright 2010 Rob Landley <>
 * See


config NICE
	bool "nice"
	default y
	  usage: nice [-n PRIORITY] command [args...]

	  Run a command line at an increased or decreased scheduling priority.

	  Higher numbers make a program yield more CPU time, from -20 (highest
	  priority) to 19 (lowest).  By default processes inherit their parent's
	  niceness (usually 0).  By default this command adds 10 to the parent's
	  priority.  Only root can set a negative niceness level.

#include "toys.h"

	long priority;

#define TT this.nice

void nice_main(void)
	if (!toys.optflags) TT.priority = 10;

	errno = 0;
	if (nice(TT.priority)==-1 && errno) perror_exit("Can't set priority");