10f66f451Sopenharmony_ci/* nice.c - Run a program at a different niceness level. 20f66f451Sopenharmony_ci * 30f66f451Sopenharmony_ci * Copyright 2010 Rob Landley <rob@landley.net> 40f66f451Sopenharmony_ci * 50f66f451Sopenharmony_ci * See http://opengroup.org/onlinepubs/9699919799/utilities/nice.html 60f66f451Sopenharmony_ci 70f66f451Sopenharmony_ciUSE_NICE(NEWTOY(nice, "^<1n#", TOYFLAG_BIN)) 80f66f451Sopenharmony_ci 90f66f451Sopenharmony_ciconfig NICE 100f66f451Sopenharmony_ci bool "nice" 110f66f451Sopenharmony_ci default y 120f66f451Sopenharmony_ci help 130f66f451Sopenharmony_ci usage: nice [-n PRIORITY] COMMAND... 140f66f451Sopenharmony_ci 150f66f451Sopenharmony_ci Run a command line at an increased or decreased scheduling priority. 160f66f451Sopenharmony_ci 170f66f451Sopenharmony_ci Higher numbers make a program yield more CPU time, from -20 (highest 180f66f451Sopenharmony_ci priority) to 19 (lowest). By default processes inherit their parent's 190f66f451Sopenharmony_ci niceness (usually 0). By default this command adds 10 to the parent's 200f66f451Sopenharmony_ci priority. Only root can set a negative niceness level. 210f66f451Sopenharmony_ci*/ 220f66f451Sopenharmony_ci 230f66f451Sopenharmony_ci#define FOR_nice 240f66f451Sopenharmony_ci#include "toys.h" 250f66f451Sopenharmony_ci 260f66f451Sopenharmony_ciGLOBALS( 270f66f451Sopenharmony_ci long n; 280f66f451Sopenharmony_ci) 290f66f451Sopenharmony_ci 300f66f451Sopenharmony_civoid nice_main(void) 310f66f451Sopenharmony_ci{ 320f66f451Sopenharmony_ci if (!toys.optflags) TT.n = 10; 330f66f451Sopenharmony_ci 340f66f451Sopenharmony_ci errno = 0; 350f66f451Sopenharmony_ci if (nice(TT.n)==-1 && errno) { 360f66f451Sopenharmony_ci toys.exitval = 125; 370f66f451Sopenharmony_ci perror_exit("Can't set priority"); 380f66f451Sopenharmony_ci } 390f66f451Sopenharmony_ci xexec(toys.optargs); 400f66f451Sopenharmony_ci} 41