add extra error tests to swap_*() && fix bytes_read bug

diff --git a/slstatus.c b/slstatus.c
index ccb7cbeb02918e32d0cddbd8b1ec0dbf375c9c60..ac09c9fff8abc42699c8a784d40bd25f0b651f5d 100644 (file)
--- a/slstatus.c
+++ b/slstatus.c
@@ -443,23 +443,20 @@ swap_free(void)
        if ((bytes_read = fread(buf, sizeof(char), sizeof(buf), fp)) == 0) {
                warn("swap_free: read error");
                fclose(fp);
+               return smprintf("%s", UNKNOWN_STR);
        }
 
        buf[bytes_read] = '\0';
        fclose(fp);
 
-       if (bytes_read == 0 || bytes_read == sizeof(buf)) {
-               warn("Failed to read from /proc/meminfo");
-               return smprintf(UNKNOWN_STR);
+       if ((match = strstr(buf, "SwapTotal")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
        }
-
-       match = strstr(buf, "SwapTotal");
        sscanf(match, "SwapTotal: %ld kB\n", &total);
-       if (total == 0) {
-               return smprintf(UNKNOWN_STR);
-       }
 
-       match = strstr(buf, "SwapFree");
+       if ((match = strstr(buf, "SwapFree")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
+       }
        sscanf(match, "SwapFree: %ld kB\n", &free);
 
        return smprintf("%f", (float)free / 1024 / 1024);
@@ -480,20 +477,19 @@ swap_perc(void)
                return smprintf(UNKNOWN_STR);
        }
 
-       bytes_read = fread(buf, sizeof(char), sizeof(buf), fp);
+       if ((bytes_read = fread(buf, sizeof(char), sizeof(buf), fp)) == 0) {
+               warn("swap_perc: read error");
+               fclose(fp);
+               return smprintf("%s", UNKNOWN_STR);
+       }
+
        buf[bytes_read] = '\0';
        fclose(fp);
 
-       if (bytes_read == 0 || bytes_read == sizeof(buf)) {
-               warn("Failed to read from /proc/meminfo");
-               return smprintf(UNKNOWN_STR);
+       if ((match = strstr(buf, "SwapTotal")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
        }
-
-       match = strstr(buf, "SwapTotal");
        sscanf(match, "SwapTotal: %ld kB\n", &total);
-       if (total == 0) {
-               return smprintf(UNKNOWN_STR);
-       }
 
        if ((match = strstr(buf, "SwapCached")) == NULL) {
                return smprintf("%s", UNKNOWN_STR);
@@ -505,7 +501,6 @@ swap_perc(void)
        }
        sscanf(match, "SwapFree: %ld kB\n", &free);
 
-
        return smprintf("%d%%", 100 * (total - free - cached) / total);
 }
 
@@ -523,19 +518,19 @@ swap_total(void)
                warn("Failed to open file /proc/meminfo");
                return smprintf(UNKNOWN_STR);
        }
-       bytes_read = fread(buf, sizeof(char), sizeof(buf), fp);
+       if ((bytes_read = fread(buf, sizeof(char), sizeof(buf), fp)) == 0) {
+               warn("swap_total: read error");
+               fclose(fp);
+               return smprintf("%s", UNKNOWN_STR);
+       }
+
        buf[bytes_read] = '\0';
        fclose(fp);
-       if (bytes_read == 0 || bytes_read == sizeof(buf)) {
-               warn("Failed to read from /proc/meminfo");
-               return smprintf(UNKNOWN_STR);
-       }
 
-       match = strstr(buf, "SwapTotal");
-       sscanf(match, "SwapTotal: %ld kB\n", &total);
-       if (total == 0) {
-               return smprintf(UNKNOWN_STR);
+       if ((match = strstr(buf, "SwapTotal")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
        }
+       sscanf(match, "SwapTotal: %ld kB\n", &total);
 
        return smprintf("%f", (float)total / 1024 / 1024);
 }
@@ -554,24 +549,28 @@ swap_used(void)
                warn("Failed to open file /proc/meminfo");
                return smprintf(UNKNOWN_STR);
        }
-       bytes_read = fread(buf, sizeof(char), sizeof(buf), fp);
+       if ((bytes_read = fread(buf, sizeof(char), sizeof(buf), fp)) == 0) {
+               warn("swap_used: read error");
+               fclose(fp);
+               return smprintf("%s", UNKNOWN_STR);
+       }
+
        buf[bytes_read] = '\0';
        fclose(fp);
-       if (bytes_read == 0 || bytes_read == sizeof(buf)) {
-               warn("Failed to read from /proc/meminfo");
-               return smprintf(UNKNOWN_STR);
-       }
 
-       match = strstr(buf, "SwapTotal");
-       sscanf(match, "SwapTotal: %ld kB\n", &total);
-       if (total == 0) {
-               return smprintf(UNKNOWN_STR);
+       if ((match = strstr(buf, "SwapTotal")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
        }
+       sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-       match = strstr(buf, "SwapCached");
+       if ((match = strstr(buf, "SwapCached")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
+       }
        sscanf(match, "SwapCached: %ld kB\n", &cached);
 
-       match = strstr(buf, "SwapFree");
+       if ((match = strstr(buf, "SwapFree")) == NULL) {
+               return smprintf("%s", UNKNOWN_STR);
+       }
        sscanf(match, "SwapFree: %ld kB\n", &free);
 
        return smprintf("%f", (float)(total - free - cached) / 1024 / 1024);