Add 'nice' and replace 'renice' with a new implementation.

AUTHORS

@@ -88,7 +88,8 @@ Glenn McGrath <bug1@iinet.net.au>
 
 Manuel Novoa III <mjn3@codepoet.org>
     cat, head, mkfifo, mknod, rmdir, sleep, tee, tty, uniq, usleep, wc, yes,
-    mesg, vconfig, make_directory, parse_mode, dirname, mode_string,
+    mesg, vconfig, nice, renice,
+    make_directory, parse_mode, dirname, mode_string,
     get_last_path_component, simplify_path, and a number trivial libbb routines
 
     also bug fixes, partial rewrites, and size optimizations in

coreutils/Config.in

@@ -329,6 +329,12 @@ config CONFIG_MV
 	help
 	  mv is used to move or rename files or directories.
 
+config CONFIG_NICE
+	bool "nice"
+	default n
+	help
+	  nice runs a program with modified scheduling priority.
+
 config CONFIG_OD
 	bool "od"
 	default n

coreutils/Makefile.in

@@ -58,6 +58,7 @@ COREUTILS-$(CONFIG_MKDIR)   	+= mkdir.o
 COREUTILS-$(CONFIG_MKFIFO)  	+= mkfifo.o
 COREUTILS-$(CONFIG_MKNOD)   	+= mknod.o
 COREUTILS-$(CONFIG_MV)      	+= mv.o
+COREUTILS-$(CONFIG_NICE)      	+= nice.o
 COREUTILS-$(CONFIG_OD)      	+= od.o
 COREUTILS-$(CONFIG_PRINTF)  	+= printf.o
 COREUTILS-$(CONFIG_PWD)     	+= pwd.o

coreutils/nice.c

@@ -0,0 +1,86 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * nice implementation for busybox
+ *
+ * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include "busybox.h"
+
+static inline int int_add_no_wrap(int a, int b)
+{
+	int s = a + b;
+
+	if (b < 0) {
+		if (s > a) s = INT_MIN;
+	} else {
+		if (s < a) s = INT_MAX;
+	}
+
+	return s;
+}
+
+int nice_main(int argc, char **argv)
+{
+	static const char Xetpriority_msg[] = "cannot %cet priority";
+
+	int old_priority, adjustment;
+
+	errno = 0;			 /* Needed for getpriority error detection. */
+	old_priority = getpriority(PRIO_PROCESS, 0);
+	if (errno) {
+		bb_perror_msg_and_die(Xetpriority_msg, 'g');
+	}
+
+	if (!*++argv) {	/* No args, so (GNU) output current nice value. */
+		bb_printf("%d\n", old_priority);
+		bb_fflush_stdout_and_exit(EXIT_SUCCESS);
+	}
+
+	adjustment = 10;			/* Set default adjustment. */
+
+	if ((argv[0][0] == '-') && (argv[0][1] == 'n') && !argv[0][2]) { /* "-n" */
+		if (argc < 4) {			/* Missing priority and/or utility! */
+			bb_show_usage();
+		}
+		adjustment = bb_xgetlarg(argv[1], 10, INT_MIN, INT_MAX);
+		argv += 2;
+	}
+
+	{  /* Set our priority.  Handle integer wrapping for old + adjust. */
+		int new_priority = int_add_no_wrap(old_priority, adjustment);
+
+		if (setpriority(PRIO_PROCESS, 0, new_priority) < 0) {
+			bb_perror_msg_and_die(Xetpriority_msg, 's');
+		}
+	}
+	
+	execvp(*argv, argv);		/* Now exec the desired program. */
+
+	/* The exec failed... */
+	bb_default_error_retval = (errno == ENOENT) ? 127 : 126; /* SUSv3 */
+	bb_perror_msg_and_die("%s", *argv);
+}

include/applets.h

@@ -412,6 +412,9 @@
 #ifdef CONFIG_NETSTAT
 	APPLET(netstat, netstat_main, _BB_DIR_BIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_NICE
+	APPLET(nice, nice_main, _BB_DIR_BIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_NSLOOKUP
 	APPLET(nslookup, nslookup_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif

include/usage.h

@@ -1813,6 +1813,13 @@
 	"\t-w raw sockets\n" \
 	"\t-x unix sockets"
 
+#define nice_trivial_usage \
+	"[-n ADJUST] [COMMAND [ARG] ...]"
+#define nice_full_usage \
+	"Nice runs a program with modified scheduling priority.\n\n" \
+	"Options:\n" \
+	"\t-n ADJUST\tAdjust the scheduling priority by ADJUST.\n" \
+
 #define nslookup_trivial_usage \
 	"[HOST] [SERVER]"
 #define nslookup_full_usage \
@@ -2011,11 +2018,14 @@
 	"\t-d\t\tdelay interval for rebooting."
 
 #define renice_trivial_usage \
-	"priority pid [pid ...]"
+	"{{-n INCREMENT} | PRIORITY} [[ -p | -g | -u ] ID ...]"
 #define renice_full_usage \
-	"Changes priority of running processes. Allowed priorities range\n" \
-	"from 20 (the process runs only when nothing else is running) to 0\n" \
-	"(default priority) to -20 (almost nothing else ever gets to run)."
+	"Changes priority of running processes.\n\n" \
+	"Options:\n" \
+	"\t-n\tadjusts current nice value (smaller is faster)\n" \
+	"\t-p\tprocess id(s) (default)\n" \
+	"\t-g\tprocess group id(s)\n" \
+	"\t-u\tprocess user name(s) and/or id(s)"
 
 #define reset_trivial_usage \
 	""

procps/renice.c

@@ -1,8 +1,8 @@
+/* vi: set sw=4 ts=4: */
 /*
- * Mini renice implementation for busybox
+ * renice implementation for busybox
  *
- *
- * Copyright (C) 2000 Dave 'Kill a Cop' Cinege <dcinege@psychosis.com>
+ * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,35 +20,133 @@
  *
  */
 
+/* Notes:
+ *   Setting an absolute priority was obsoleted in SUSv2 and removed
+ *   in SUSv3.  However, the common linux version of renice does
+ *   absolute and not relative.  So we'll continue supporting absolute,
+ *   although the stdout logging has been removed since both SUSv2 and
+ *   SUSv3 specify that stdout isn't used.
+ *
+ *   This version is lenient in that it doesn't require any IDs.  The
+ *   options -p, -g, and -u are treated as mode switches for the
+ *   following IDs (if any).  Multiple switches are allowed.
+ */
+
 #include <stdio.h>
-#include <errno.h>
 #include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+#include <unistd.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include "busybox.h"
 
+#if (PRIO_PROCESS < CHAR_MIN) || (PRIO_PROCESS > CHAR_MAX)
+#error Assumption violated : PRIO_PROCESS value
+#endif
+#if (PRIO_PGRP < CHAR_MIN) || (PRIO_PGRP > CHAR_MAX)
+#error Assumption violated : PRIO_PGRP value
+#endif
+#if (PRIO_USER < CHAR_MIN) || (PRIO_USER > CHAR_MAX)
+#error Assumption violated : PRIO_USER value
+#endif
 
-extern int renice_main(int argc, char **argv)
+static inline int int_add_no_wrap(int a, int b)
 {
-	int prio, status = EXIT_SUCCESS;
+	int s = a + b;
 
-	if (argc < 3)	bb_show_usage();
-
-	prio = atoi(*++argv);
-	if (prio > 20)		prio = 20;
-	if (prio < -20)		prio = -20;
-
-	while (*++argv) {
-		int ps = atoi(*argv);
-		int oldp = getpriority(PRIO_PROCESS, ps);
-
-		if (setpriority(PRIO_PROCESS, ps, prio) == 0) {
-			printf("%d: old priority %d, new priority %d\n", ps, oldp, prio );
-		} else {
-			bb_perror_msg("%d: setpriority", ps);
-			status = EXIT_FAILURE;
-		}
+	if (b < 0) {
+		if (s > a) s = INT_MIN;
+	} else {
+		if (s < a) s = INT_MAX;
 	}
 
-	return status;
+	return s;
+}
+
+int renice_main(int argc, char **argv)
+{
+	static const char Xetpriority_msg[] = "%d : %cetpriority";
+
+	int retval = EXIT_SUCCESS;
+	int which = PRIO_PROCESS;	/* Default 'which' value. */
+	int use_relative = 0;
+	int adjustment, new_priority;
+	id_t who;
+
+	++argv;
+
+	/* Check if we are using a relative adjustment. */
+	if (argv[0] && (argv[0][0] == '-') && (argv[0][1] == 'n') && !argv[0][2]) {
+		use_relative = 1;
+		++argv;
+	}
+
+	if (!*argv) {				/* No args?  Then show usage. */
+		bb_show_usage();
+	}
+
+	/* Get the priority adjustment (absolute or relative). */
+	adjustment = bb_xgetlarg(*argv, 10, INT_MIN, INT_MAX);
+
+	while (*++argv) {
+		/* Check for a mode switch. */
+		if ((argv[0][0] == '-') && argv[0][1] && !argv[0][2]) {
+			static const char opts[]
+				= { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
+			const char *p;
+			if ((p = strchr(opts, argv[0][1]))) {
+				which = p[4];
+				continue;
+			}
+		}
+
+		/* Process an ID arg. */
+		if (which == PRIO_USER) {
+			struct passwd *p;
+			if (!(p = getpwnam(*argv))) {
+				bb_error_msg("unknown user: %s", *argv);
+				goto HAD_ERROR;
+			}
+			who = p->pw_uid;
+		} else {
+			char *e;
+			errno = 0;
+			who = strtoul(*argv, &e, 10);
+			if (*e || (*argv == e) || errno) {
+				bb_error_msg("bad value: %s", *argv);
+				goto HAD_ERROR;
+			}
+		}
+
+		/* Get priority to use, and set it. */
+		if (use_relative) {
+			int old_priority;
+
+			errno = 0;	 /* Needed for getpriority error detection. */
+			old_priority = getpriority(which, who);
+			if (errno) {
+				bb_perror_msg(Xetpriority_msg, who, 'g');
+				goto HAD_ERROR;
+			}
+
+			new_priority = int_add_no_wrap(old_priority, adjustment);
+		} else {
+			new_priority = adjustment;
+		}
+
+		if (setpriority(which, who, new_priority) == 0) {
+			continue;
+		}
+
+		bb_perror_msg(Xetpriority_msg, who, 's');
+	HAD_ERROR:
+		retval = EXIT_FAILURE;
+	}
+
+	/* No need to check for errors outputing to stderr since, if it
+	 * was used, the HAD_ERROR label was reached and retval was set. */
+
+	return retval;
 }