swap_perc: check for division by zero

[slstatus.git] / components / swap.c

diff --git a/components/swap.c b/components/swap.c
index fe779db..465ffd4 100644 (file)
--- a/components/swap.c
+++ b/components/swap.c
@@ -1,11 +1,11 @@
 /* See LICENSE file for copyright and license details. */
 /* See LICENSE file for copyright and license details. */

-#if defined(__linux__)
-       #include <errno.h>
-       #include <stdio.h>
-       #include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>

 
 

-       #include "../util.h"
+#include "../util.h"

 
 

+#if defined(__linux__)

        static size_t
        pread(const char *path, char *buf, size_t bufsiz)
        {
        static size_t
        pread(const char *path, char *buf, size_t bufsiz)
        {


@@ -13,13 +13,11 @@
                size_t bytes_read;
 
                if (!(fp = fopen(path, "r"))) {
                size_t bytes_read;
 
                if (!(fp = fopen(path, "r"))) {

-                       fprintf(stderr, "fopen '%s': %s\n", path,
-                               strerror(errno));
+                       warn("fopen '%s':", path);

                        return 0;
                }
                        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;
                }
                        fclose(fp);
                        return 0;
                }


@@ -40,15 +38,17 @@
                        return NULL;
                }
 
                        return NULL;
                }
 

-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 

-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapFree: %ld kB\n", &free);
 
                sscanf(match, "SwapFree: %ld kB\n", &free);
 

-               return bprintf("%f", (float)free / 1024 / 1024);
+               return fmt_human_2(free * 1024, "B");

        }
 
        const char *
        }
 
        const char *


@@ -61,19 +61,26 @@
                        return NULL;
                }
 
                        return NULL;
                }
 

-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 

-               if ((match = strstr(buf, "SwapCached")) == NULL)
+               if (!(match = strstr(buf, "SwapCached"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapCached: %ld kB\n", &cached);
 
                sscanf(match, "SwapCached: %ld kB\n", &cached);
 

-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapFree: %ld kB\n", &free);
 
                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 *
        }
 
        const char *


@@ -86,11 +93,12 @@
                        return NULL;
                }
 
                        return NULL;
                }
 

-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 

-               return bprintf("%f", (float)total / 1024 / 1024);
+               return fmt_human_2(total * 1024, "B");

        }
 
        const char *
        }
 
        const char *


@@ -103,20 +111,103 @@
                        return NULL;
                }
 
                        return NULL;
                }
 

-               if ((match = strstr(buf, "SwapTotal")) == NULL)
+               if (!(match = strstr(buf, "SwapTotal"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapTotal: %ld kB\n", &total);
 
                sscanf(match, "SwapTotal: %ld kB\n", &total);
 

-               if ((match = strstr(buf, "SwapCached")) == NULL)
+               if (!(match = strstr(buf, "SwapCached"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapCached: %ld kB\n", &cached);
 
                sscanf(match, "SwapCached: %ld kB\n", &cached);
 

-               if ((match = strstr(buf, "SwapFree")) == NULL)
+               if (!(match = strstr(buf, "SwapFree"))) {

                        return NULL;
                        return NULL;

+               }

                sscanf(match, "SwapFree: %ld kB\n", &free);
 
                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__)
        }
 #elif defined(__OpenBSD__)

-       /* unimplemented */
+       #include <stdlib.h>
+       #include <sys/param.h> /* dbtob */
+       #include <sys/swap.h>
+       #include <sys/types.h>
+       #include <unistd.h>
+
+       static void
+       getstats(int *total, int *used)
+       {
+               struct swapent *sep, *fsep;
+               int rnswap, nswap, i;
+
+               nswap = swapctl(SWAP_NSWAP, 0, 0);
+               if (nswap < 1) {
+                       warn("swaptctl 'SWAP_NSWAP':");
+               }
+
+               fsep = sep = calloc(nswap, sizeof(*sep));
+               if (!sep) {
+                       warn("calloc 'nswap':");
+               }
+
+               rnswap = swapctl(SWAP_STATS, (void *)sep, nswap);
+               if (rnswap < 0) {
+                       warn("swapctl 'SWAP_STATA':");
+               }
+
+               if (nswap != rnswap) {
+                       warn("getstats: SWAP_STATS != SWAP_NSWAP");
+               }
+
+               *total = 0;
+               *used = 0;
+
+               for (i = 0; i < rnswap; i++) {
+                       *total += sep->se_nblks >> 1;
+                       *used += sep->se_inuse >> 1;
+               }
+
+               free(fsep);
+       }
+
+       const char *
+       swap_free(void)
+       {
+               int total, used;
+
+               getstats(&total, &used);
+
+               return fmt_human_2((total - used) * 1024, "B");
+       }
+
+       const char *
+       swap_perc(void)
+       {
+               int total, used;
+
+               getstats(&total, &used);
+
+               return bprintf("%d%%", 100 * used / total);
+       }
+
+       const char *
+       swap_total(void)
+       {
+               int total, used;
+
+               getstats(&total, &used);
+
+               return fmt_human_2(total * 1024, "B");
+       }
+
+       const char *
+       swap_used(void)
+       {
+               int total, used;
+
+               getstats(&total, &used);
+
+               return fmt_human_2(used * 1024, "B");
+       }

 #endif
 #endif