Error handling: Never output null as full_text (JSON), prefix messages with i3status...

[i3/i3status] / src / print_cpu_usage.c

diff --git a/src/print_cpu_usage.c b/src/print_cpu_usage.c
index d80693d312f878fc95721cc1b797a77587e6afad..782084014433e831ff6ff46984f7247012b67945 100644 (file)
--- a/src/print_cpu_usage.c
+++ b/src/print_cpu_usage.c
@@ -3,6 +3,15 @@
 #include <limits.h>
 #include <stdio.h>
 #include <string.h>
+#include <yajl/yajl_gen.h>
+#include <yajl/yajl_version.h>
+
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/dkstat.h>
+#endif
 
 #include "i3status.h"
 
@@ -14,37 +23,75 @@ static int prev_idle  = 0;
  * percentage.
  *
  */
-void print_cpu_usage(const char *format) { 
+void print_cpu_usage(yajl_gen json_gen, char *buffer, const char *format) {
         const char *walk;
+        char *outwalk = buffer;
         char buf[1024];
-        int curr_user, curr_nice, curr_system, curr_idle, curr_total;
+        int curr_user = 0, curr_nice = 0, curr_system = 0, curr_idle = 0, curr_total;
         int diff_idle, diff_total, diff_usage;
 
 #if defined(LINUX)
         static char statpath[512];
         strcpy(statpath, "/proc/stat");
-        if (!slurp(statpath, buf, sizeof(buf)))
-                die("could not read %s\n", statpath);
+        if (!slurp(statpath, buf, sizeof(buf)) ||
+            sscanf(buf, "cpu %d %d %d %d", &curr_user, &curr_nice, &curr_system, &curr_idle) != 4)
+                goto error;
 
-        if (sscanf(buf, "cpu %d %d %d %d", &curr_user, &curr_nice, &curr_system, &curr_idle) != 4)
-                die("could not read cpu utilization\n");
+        curr_total = curr_user + curr_nice + curr_system + curr_idle;
+        diff_idle  = curr_idle - prev_idle;
+        diff_total = curr_total - prev_total;
+        diff_usage = (1000 * (diff_total - diff_idle)/diff_total + 5)/10;
+        prev_total = curr_total;
+        prev_idle  = curr_idle;
+#elif defined(__FreeBSD__) || defined(__OpenBSD__)
+
+#if defined(__FreeBSD__)
+        size_t size;
+        long cp_time[CPUSTATES];
+        size = sizeof cp_time;
+        if (sysctlbyname("kern.cp_time", &cp_time, &size, NULL, 0) < 0)
+                goto error;
+#else
+       /* This information is taken from the boot cpu, any other cpus are currently ignored. */
+       long cp_time[CPUSTATES];
+       int mib[2];
+       size_t size = sizeof(cp_time);
+
+       mib[0] = CTL_KERN;
+       mib[1] = KERN_CPTIME;
 
+       if (sysctl(mib, 2, cp_time, &size, NULL, 0))
+               goto error;
+#endif
+
+        curr_user = cp_time[CP_USER];
+        curr_nice = cp_time[CP_NICE];
+        curr_system = cp_time[CP_SYS];
+        curr_idle = cp_time[CP_IDLE];
         curr_total = curr_user + curr_nice + curr_system + curr_idle;
         diff_idle  = curr_idle - prev_idle;
         diff_total = curr_total - prev_total;
         diff_usage = (1000 * (diff_total - diff_idle)/diff_total + 5)/10;
         prev_total = curr_total;
         prev_idle  = curr_idle;
+#else
+        goto error;
 #endif
         for (walk = format; *walk != '\0'; walk++) {
                 if (*walk != '%') {
-                        putchar(*walk);
+                        *(outwalk++) = *walk;
                         continue;
                 }
 
                 if (strncmp(walk+1, "usage", strlen("usage")) == 0) {
-                        printf("%02d%%", diff_usage);
+                        outwalk += sprintf(outwalk, "%02d%%", diff_usage);
                         walk += strlen("usage");
                 }
         }
+
+        OUTPUT_FULL_TEXT(buffer);
+        return;
+error:
+        OUTPUT_FULL_TEXT("cant read cpu usage");
+        (void)fputs("i3status: Cannot read CPU usage\n", stderr);
 }