changeset 374:633a5bf9509d

Add command "nice".
author Rob Landley <rob@landley.net>
date Wed, 06 Jan 2010 05:29:53 -0600
parents 5e68c7cab1a4
children 9f4e5e15597c
files toys/nice.c
diffstat 1 files changed, 44 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/nice.c	Wed Jan 06 05:29:53 2010 -0600
@@ -0,0 +1,44 @@
+/* vi: set sw=4 ts=4:
+ *
+ * nice.c - Run a program at a different niceness level.
+ *
+ * Copyright 2010 Rob Landley <rob@landley.net>
+ *
+ * See http://www.opengroup.org/onlinepubs/9699919799/utilities/nice.html
+
+USE_NICE(NEWTOY(nice, "^<1n#", TOYFLAG_USR|TOYFLAG_BIN))
+
+config NICE
+	bool "nice"
+	default y
+	help
+	  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 (lowest
+	  priority) to -19 (highest).  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"
+
+// Hello doesn't use these globals, they're here for example/skeleton purposes.
+
+DEFINE_GLOBALS(
+	long priority;
+)
+
+#define TT this.nice
+
+void nice_main(void)
+{
+	if (!toys.optflags) TT.priority = 10;
+
+	nice(TT.priority);
+	if (getpriority(PRIO_PROCESS, getpid()) != TT.priority)
+		perror_exit("Can't set priority");
+
+	xexec(toys.optargs);
+}