From 4a85d56c4cda90d0c175f29eb320375d14ead507 Mon Sep 17 00:00:00 2001
From: haroon maqsood <maqsood3525@live.com>
Date: Fri, 6 Jul 2018 16:17:57 +0200
Subject: [PATCH] nproc: implement --all --ignore=N

function                                             old     new   delta
nproc_main                                            98     242    +144
packed_usage                                       32799   32816     +17
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 161/0)             Total: 161 bytes

Signed-off-by: haroon maqsood <maqsood3525@live.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 coreutils/nproc.c | 44 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 34 insertions(+), 10 deletions(-)

diff --git a/coreutils/nproc.c b/coreutils/nproc.c
index 336b176ca..0ea8d1001 100644
--- a/coreutils/nproc.c
+++ b/coreutils/nproc.c
@@ -14,10 +14,14 @@
 //kbuild:lib-$(CONFIG_NPROC) += nproc.o
 
 //usage:#define nproc_trivial_usage
-//usage:	""
-//TODO: "[--all] [--ignore=N]"
+//usage:	""IF_LONG_OPTS("--all --ignore=N")
 //usage:#define nproc_full_usage "\n\n"
-//usage:	"Print number of CPUs"
+//usage:	"Print number of available CPUs"
+//usage:	IF_LONG_OPTS(
+//usage:     "\n"
+//usage:     "\n	--all		Number of installed CPUs"
+//usage:     "\n	--ignore=N	Exclude N CPUs"
+//usage:	)
 
 #include <sched.h>
 #include "libbb.h"
@@ -26,13 +30,30 @@ 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;
-
-	//getopt32(argv, "");
-
-	//if --all, count /sys/devices/system/cpu/cpuN dirs, else:
+	int count = 0;
+#if ENABLE_LONG_OPTS
+	int ignore = 0;
+	int opts = getopt32long(argv, "\xfe:+",
+			"ignore\0" Required_argument "\xfe"
+			"all\0"    No_argument       "\xff"
+			, &ignore
+	);
 
+	if (opts & (1 << 1)) {
+		DIR *cpusd = opendir("/sys/devices/system/cpu");
+		if (cpusd) {
+			struct dirent *de;
+			while (NULL != (de = readdir(cpusd))) {
+				char *cpuid = strstr(de->d_name, "cpu");
+				if (cpuid && isdigit(cpuid[strlen(cpuid) - 1]))
+					count++;
+			}
+			closedir(cpusd);
+		}
+	} else
+#endif
 	if (sched_getaffinity(0, sizeof(mask), (void*)mask) == 0) {
+		int i;
 		for (i = 0; i < ARRAY_SIZE(mask); i++) {
 			unsigned long m = mask[i];
 			while (m) {
@@ -42,8 +63,11 @@ int nproc_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 			}
 		}
 	}
-	if (count == 0)
-		count++;
+
+	IF_LONG_OPTS(count -= ignore;)
+	if (count <= 0)
+		count = 1;
+
 	printf("%u\n", count);
 
 	return 0;