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

3 files changed, 93 insertions, 0 deletions

diff --git a/coreutils/Config.in b/coreutils/Config.in
index 4aff5ce69..a299506e6 100644
--- a/coreutils/Config.in
+++ b/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
diff --git a/coreutils/Makefile.in b/coreutils/Makefile.in
index aacb813b3..63823657f 100644
--- a/coreutils/Makefile.in
+++ b/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
diff --git a/coreutils/nice.c b/coreutils/nice.c
new file mode 100644
index 000000000..b66f9d82d
--- /dev/null
+++ b/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);
+}