1 /*
2 * Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
3 *
4 * Licensed under GPLv2, see LICENSE in this source tree
5 */
6 //config:config NPROC
7 //config: bool "nproc (3.7 kb)"
8 //config: default y
9 //config: help
10 //config: Print number of CPUs
11
12 //applet:IF_NPROC(APPLET_NOFORK(nproc, nproc, BB_DIR_USR_BIN, BB_SUID_DROP, nproc))
13
14 //kbuild:lib-$(CONFIG_NPROC) += nproc.o
15
16 //usage:#define nproc_trivial_usage
17 //usage: ""IF_LONG_OPTS("[--all] [--ignore=N]")
18 //usage:#define nproc_full_usage "\n\n"
19 //usage: "Print number of available CPUs"
20 //usage: IF_LONG_OPTS(
21 //usage: "\n"
22 //usage: "\n --all Number of installed CPUs"
23 //usage: "\n --ignore=N Exclude N CPUs"
24 //usage: )
25
26 #include <sched.h>
27 #include "libbb.h"
28
29 int nproc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
nproc_main(int argc UNUSED_PARAM,char ** argv UNUSED_PARAM)30 int nproc_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
31 {
32 unsigned long mask[1024];
33 int count = 0;
34 #if ENABLE_LONG_OPTS
35 int ignore = 0;
36 int opts = getopt32long(argv, "\xfe:+",
37 "ignore\0" Required_argument "\xfe"
38 "all\0" No_argument "\xff"
39 , &ignore
40 );
41
42 if (opts & (1 << 1)) {
43 DIR *cpusd = opendir("/sys/devices/system/cpu");
44 if (cpusd) {
45 struct dirent *de;
46 while (NULL != (de = readdir(cpusd))) {
47 char *cpuid = strstr(de->d_name, "cpu");
48 if (cpuid && isdigit(cpuid[strlen(cpuid) - 1]))
49 count++;
50 }
51 IF_FEATURE_CLEAN_UP(closedir(cpusd);)
52 }
53 } else
54 #endif
55 if (sched_getaffinity(0, sizeof(mask), (void*)mask) == 0) {
56 int i;
57 for (i = 0; i < ARRAY_SIZE(mask); i++) {
58 unsigned long m = mask[i];
59 while (m) {
60 if (m & 1)
61 count++;
62 m >>= 1;
63 }
64 }
65 }
66
67 IF_LONG_OPTS(count -= ignore;)
68 if (count <= 0)
69 count = 1;
70
71 printf("%u\n", count);
72
73 return 0;
74 }
75