free: handle "cached" value too

function                                             old     new   delta
free_main                                            356     481    +125

Signed-off-by: Guillermo Rodriguez <guille.rodriguez@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/procps/free.c b/procps/free.c
index 47f2fc3b2597eb3f23b4cda2e899cf41a3802afd..0d023f7401871f7a9be6f162bd2320b79e3b3dae 100644 (file)
--- a/procps/free.c
+++ b/procps/free.c
@@ -44,11 +44,28 @@ static unsigned long long scale(unsigned long d)
        return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
 }
 
+static unsigned long parse_cached_kb(void)
+{
+       char buf[60]; /* actual lines we expect are ~30 chars or less */
+       FILE *fp;
+       unsigned long cached = 0;
+
+       fp = xfopen_for_read("/proc/meminfo");
+       while (fgets(buf, sizeof(buf), fp) != NULL) {
+               if (sscanf(buf, "Cached: %lu %*s\n", &cached) == 1)
+                       break;
+       }
+       if (ENABLE_FEATURE_CLEAN_UP)
+               fclose(fp);
+
+       return cached;
+}
 
 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 long long cached;
 
        INIT_G();
 
@@ -73,49 +90,47 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
                }
        }
 #endif
-
-       sysinfo(&info);
-
-       /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
-       G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
-
-       printf("     %13s%13s%13s%13s%13s\n",
+       printf("       %11s%11s%11s%11s%11s%11s\n"
+       "Mem:   ",
                "total",
                "used",
                "free",
-               "shared", "buffers" /* swap and total don't have these columns */
-               /* procps version 3.2.8 also shows "cached" column, but
-                * sysinfo() does not provide this value, need to parse
-                * /proc/meminfo instead and get "Cached: NNN kB" from there.
-                */
+               "shared", "buffers", "cached" /* swap and total don't have these columns */
        );
 
-#define FIELDS_5 "%13llu%13llu%13llu%13llu%13llu\n"
-#define FIELDS_3 (FIELDS_5 + 2*6)
-#define FIELDS_2 (FIELDS_5 + 3*6)
+       sysinfo(&info);
+       /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
+       G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
+       /* Extract cached from /proc/meminfo and convert to mem_units */
+       cached = ((unsigned long long) parse_cached_kb() * 1024) / G.mem_unit;
+
+#define FIELDS_6 "%11llu%11llu%11llu%11llu%11llu%11llu\n"
+#define FIELDS_3 (FIELDS_6 + 3*6)
+#define FIELDS_2 (FIELDS_6 + 4*6)
 
-       printf("Mem: ");
-       printf(FIELDS_5,
-               scale(info.totalram),
-               scale(info.totalram - info.freeram),
-               scale(info.freeram),
-               scale(info.sharedram),
-               scale(info.bufferram)
+       printf(FIELDS_6,
+               scale(info.totalram),                //total
+               scale(info.totalram - info.freeram), //used
+               scale(info.freeram),                 //free
+               scale(info.sharedram),               //shared
+               scale(info.bufferram),               //buffers
+               scale(cached)                        //cached
        );
        /* 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:      ");
+        * buffer cache as free memory. */
+       printf("-/+ buffers/cache:");
+       cached += info.freeram;
+       cached += info.bufferram;
        printf(FIELDS_2,
-               scale(info.totalram - info.freeram - info.bufferram),
-               scale(info.freeram + info.bufferram)
+               scale(info.totalram - cached), //used
+               scale(cached)                  //free
        );
 #if BB_MMU
-       printf("Swap:");
+       printf("Swap:  ");
        printf(FIELDS_3,
-               scale(info.totalswap),
-               scale(info.totalswap - info.freeswap),
-               scale(info.freeswap)
+               scale(info.totalswap),                 //total
+               scale(info.totalswap - info.freeswap), //used
+               scale(info.freeswap)                   //free
        );
 #endif
        return EXIT_SUCCESS;