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>

1 files 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;