free: add -b/k/m/g options; remove 4 TB limitation. +100 bytes

Based on patch by Stefan Tomanek (stefan@pico.ruhr.de)

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

1 files changed, 56 insertions, 42 deletions

diff --git a/procps/free.c b/procps/free.c
index be65f46f1..efbac5ba6 100644
--- a/procps/free.c
+++ b/procps/free.c
@@ -11,47 +11,58 @@
 
 #include "libbb.h"
 
+struct globals {
+        unsigned mem_unit;
+#if ENABLE_DESKTOP
+        unsigned unit_steps;
+# define G_unit_steps G.unit_steps
+#else
+# define G_unit_steps 10
+#endif
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
+
+
+static unsigned long long scale(unsigned long d)
+{
+        return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
+}
+
+
 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
 {
         struct sysinfo info;
-        unsigned mem_unit;
+
+        INIT_G();
 
 #if ENABLE_DESKTOP
-        if (argv[1] && argv[1][0] == '-')
-                bb_show_usage();
+        G.unit_steps = 10;
+        if (argv[1] && argv[1][0] == '-') {
+                switch (argv[1][1]) {
+                case 'b':
+                        G.unit_steps = 0;
+                        break;
+                case 'k': /* 2^10 */
+                        /* G.unit_steps = 10; - already is */
+                        break;
+                case 'm': /* 2^(2*10) */
+                        G.unit_steps = 20;
+                        break;
+                case 'g': /* 2^(3*10) */
+                        G.unit_steps = 30;
+                        break;
+                default:
+                        bb_show_usage();
+                }
+        }
 #endif
 
         sysinfo(&info);
 
         /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
-        mem_unit = 1;
-        if (info.mem_unit != 0) {
-                mem_unit = info.mem_unit;
-        }
-
-        /* Convert values to kbytes */
-        if (mem_unit == 1) {
-                info.totalram >>= 10;
-                info.freeram >>= 10;
-#if BB_MMU
-                info.totalswap >>= 10;
-                info.freeswap >>= 10;
-#endif
-                info.sharedram >>= 10;
-                info.bufferram >>= 10;
-        } else {
-                mem_unit >>= 10;
-                /* TODO:  Make all this stuff not overflow when mem >= 4 Tb */
-                info.totalram *= mem_unit;
-                info.freeram *= mem_unit;
-#if BB_MMU
-                info.totalswap *= mem_unit;
-                info.freeswap *= mem_unit;
-#endif
-                info.sharedram *= mem_unit;
-                info.bufferram *= mem_unit;
-        }
+        G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
 
         printf("     %13s%13s%13s%13s%13s\n",
                 "total",
@@ -63,30 +74,33 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
                  * /proc/meminfo instead and get "Cached: NNN kB" from there.
                  */
         );
-#define FIELDS_5 "%13lu%13lu%13lu%13lu%13lu\n"
-#define FIELDS_3 (FIELDS_5 + 2*5)
-#define FIELDS_2 (FIELDS_5 + 3*5)
+
+#define FIELDS_5 "%13llu%13llu%13llu%13llu%13llu\n"
+#define FIELDS_3 (FIELDS_5 + 2*6)
+#define FIELDS_2 (FIELDS_5 + 3*6)
+
         printf("Mem: ");
         printf(FIELDS_5,
-                info.totalram,
-                info.totalram - info.freeram,
-                info.freeram,
-                info.sharedram, info.bufferram
+                scale(info.totalram),
+                scale(info.totalram - info.freeram),
+                scale(info.freeram),
+                scale(info.sharedram),
+                scale(info.bufferram)
         );
         /* Show alternate, more meaningful busy/free numbers by counting
          * buffer cache as free memory (make it "-/+ buffers/cache"
          * if/when we add support for "cached" column): */
         printf("-/+ buffers:      ");
         printf(FIELDS_2,
-                info.totalram - info.freeram - info.bufferram,
-                info.freeram + info.bufferram
+                scale(info.totalram - info.freeram - info.bufferram),
+                scale(info.freeram + info.bufferram)
         );
 #if BB_MMU
         printf("Swap:");
         printf(FIELDS_3,
-                info.totalswap,
-                info.totalswap - info.freeswap,
-                info.freeswap
+                scale(info.totalswap),
+                scale(info.totalswap - info.freeswap),
+                scale(info.freeswap)
         );
 #endif
         return EXIT_SUCCESS;