swap_perc: check for division by zero

[slstatus.git] / components / swap.c

diff --git a/components/swap.c b/components/swap.c
index f6f8993..465ffd4 100644 (file)
--- a/components/swap.c
+++ b/components/swap.c
@@ -13,13 +13,11 @@
                size_t bytes_read;
 
                if (!(fp = fopen(path, "r"))) {
-                       fprintf(stderr, "fopen '%s': %s\n", path,
-                               strerror(errno));
+                       warn("fopen '%s':", path);
                        return 0;
                }
-               if ((bytes_read = fread(buf, sizeof(char), bufsiz, fp)) == 0) {
-                       fprintf(stderr, "fread '%s': %s\n", path,
-                               strerror(errno));
+               if (!(bytes_read = fread(buf, sizeof(char), bufsiz, fp))) {
+                       warn("fread '%s':", path);
                        fclose(fp);
                        return 0;
                }
@@ -40,15 +38,17 @@
                        return NULL;
                }
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {
                        return NULL;
+               }
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {
                        return NULL;
+               }
                sscanf(match, "SwapFree: %ld kB\n", &free);
 
-               return bprintf("%f", (float)free / 1024 / 1024);
+               return fmt_human_2(free * 1024, "B");
        }
 
        const char *
@@ -61,19 +61,26 @@
                        return NULL;
                }
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {
                        return NULL;
+               }
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-               if ((match = strstr(buf, "SwapCached")) == NULL)
+               if (!(match = strstr(buf, "SwapCached"))) {
                        return NULL;
+               }
                sscanf(match, "SwapCached: %ld kB\n", &cached);
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {
                        return NULL;
+               }
                sscanf(match, "SwapFree: %ld kB\n", &free);
 
-               return bprintf("%d", 100 * (total - free - cached) / total);
+               if (total == 0) {
+                       return NULL;
+               }
+
+               return bprintf("%d%%", 100 * (total - free - cached) / total);
        }
 
        const char *
@@ -86,11 +93,12 @@
                        return NULL;
                }
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {
                        return NULL;
+               }
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-               return bprintf("%f", (float)total / 1024 / 1024);
+               return fmt_human_2(total * 1024, "B");
        }
 
        const char *
@@ -103,19 +111,22 @@
                        return NULL;
                }
 
-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {
                        return NULL;
+               }
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-               if ((match = strstr(buf, "SwapCached")) == NULL)
+               if (!(match = strstr(buf, "SwapCached"))) {
                        return NULL;
+               }
                sscanf(match, "SwapCached: %ld kB\n", &cached);
 
-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {
                        return NULL;
+               }
                sscanf(match, "SwapFree: %ld kB\n", &free);
 
-               return bprintf("%f", (float)(total - free - cached) / 1024 / 1024);
+               return fmt_human_2((total - free - cached) * 1024, "B");
        }
 #elif defined(__OpenBSD__)
        #include <stdlib.h>
@@ -124,8 +135,6 @@
        #include <sys/types.h>
        #include <unistd.h>
 
-       #define dbtoqb(b) dbtob((int64_t)(b))
-
        static void
        getstats(int *total, int *used)
        {
@@ -133,26 +142,30 @@
                int rnswap, nswap, i;
 
                nswap = swapctl(SWAP_NSWAP, 0, 0);
-               if (nswap < 1)
-                       fprintf(stderr, "swaptctl 'SWAP_NSWAP': %s\n", strerror(errno));
+               if (nswap < 1) {
+                       warn("swaptctl 'SWAP_NSWAP':");
+               }
 
                fsep = sep = calloc(nswap, sizeof(*sep));
-               if (sep == NULL)
-                       fprintf(stderr, "calloc 'nswap': %s\n", strerror(errno));
+               if (!sep) {
+                       warn("calloc 'nswap':");
+               }
 
                rnswap = swapctl(SWAP_STATS, (void *)sep, nswap);
-               if (rnswap < 0)
-                       fprintf(stderr, "swapctl 'SWAP_STATA': %s\n", strerror(errno));
+               if (rnswap < 0) {
+                       warn("swapctl 'SWAP_STATA':");
+               }
 
-               if (nswap != rnswap)
-                       fprintf(stderr, "SWAP_STATS != SWAP_NSWAP\n");
+               if (nswap != rnswap) {
+                       warn("getstats: SWAP_STATS != SWAP_NSWAP");
+               }
 
                *total = 0;
                *used = 0;
 
                for (i = 0; i < rnswap; i++) {
-                       *total += dbtoqb(sep->se_nblks);
-                       *used += dbtoqb(sep->se_inuse);
+                       *total += sep->se_nblks >> 1;
+                       *used += sep->se_inuse >> 1;
                }
 
                free(fsep);
@@ -165,7 +178,7 @@
 
                getstats(&total, &used);
 
-               return bprintf("%f", (float)(total - used) / 1024 / 1024 / 1024);
+               return fmt_human_2((total - used) * 1024, "B");
        }
 
        const char *
@@ -175,7 +188,7 @@
 
                getstats(&total, &used);
 
-               return bprintf("%d", 100 * used / total);
+               return bprintf("%d%%", 100 * used / total);
        }
 
        const char *
@@ -185,7 +198,7 @@
 
                getstats(&total, &used);
 
-               return bprintf("%f", (float)total / 1024 / 1024 / 1024);
+               return fmt_human_2(total * 1024, "B");
        }
 
        const char *
@@ -195,6 +208,6 @@
 
                getstats(&total, &used);
 
-               return bprintf("%f", (float)used / 1024 / 1024 / 1024);
+               return fmt_human_2(used * 1024, "B");
        }
 #endif