nproc: new applet

function                                             old     new   delta
nproc_main                                             -      98     +98
applet_names                                        2584    2590      +6
applet_main                                         1496    1500      +4
applet_install_loc                                   187     188      +1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/coreutils/nproc.c b/coreutils/nproc.c
new file mode 100644 (file)
index 0000000..d7c6a4b
--- /dev/null
+++ b/coreutils/nproc.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * Licensed under GPLv2, see LICENSE in this source tree
+ */
+//config:config NPROC
+//config:      bool "nproc"
+//config:      default y
+//config:      help
+//config:        Print number of CPUs
+
+//applet:IF_NPROC(APPLET(nproc, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_NPROC) += nproc.o
+
+//usage:#define nproc_trivial_usage
+//usage:       ""
+//TODO: "[--all] [--ignore=N]"
+//usage:#define nproc_full_usage "\n\n"
+//usage:       "Print number of CPUs"
+
+#include <sched.h>
+#include "libbb.h"
+
+int nproc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int nproc_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
+{
+       unsigned long mask[1024];
+       unsigned i, count = 0;
+
+       //applet_long_options = ...;
+       //getopt32(argv, "");
+
+       //if --all, count /sys/devices/system/cpu/cpuN dirs, else:
+
+       if (sched_getaffinity(0, sizeof(mask), (void*)mask) == 0) {
+               for (i = 0; i < ARRAY_SIZE(mask); i++) {
+                       unsigned long m = mask[i];
+                       while (m) {
+                               if (m & 1)
+                                       count++;
+                               m >>= 1;
+                       }
+               }
+       }
+       if (count == 0)
+               count++;
+       printf("%u\n", count);
+
+       return 0;
+}