battery: Minor coding style fixes

[slstatus.git] / components / battery.c

diff --git a/components/battery.c b/components/battery.c
index 3965e8f..6105a37 100644 (file)
--- a/components/battery.c
+++ b/components/battery.c
@@ -7,6 +7,29 @@
 
 #if defined(__linux__)
        #include <limits.h>
+       #include <unistd.h>
+
+       #define CHARGE_NOW "/sys/class/power_supply/%s/charge_now"
+       #define ENERGY_NOW "/sys/class/power_supply/%s/energy_now"
+       #define CURRENT_NOW "/sys/class/power_supply/%s/current_now"
+       #define POWER_NOW "/sys/class/power_supply/%s/power_now"
+
+       static const char *
+       pick(const char *bat, const char *f1, const char *f2, char *path,
+            size_t length)
+       {
+               if (esnprintf(path, length, f1, bat) > 0 &&
+                   access(path, R_OK) == 0) {
+                       return f1;
+               }
+
+               if (esnprintf(path, length, f2, bat) > 0 &&
+                   access(path, R_OK) == 0) {
+                       return f2;
+               }
+
+               return NULL;
+       }
 
        const char *
        battery_perc(const char *bat)
@@ -14,15 +37,22 @@
                int perc;
                char path[PATH_MAX];
 
-               snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-                        bat, "/capacity");
-               return (pscanf(path, "%d", &perc) == 1) ? bprintf("%d", perc) : NULL;
+               if (esnprintf(path, sizeof(path),
+                             "/sys/class/power_supply/%s/capacity",
+                             bat) < 0) {
+                       return NULL;
+               }
+               if (pscanf(path, "%d", &perc) != 1) {
+                       return NULL;
+               }
+
+               return bprintf("%d", perc);
        }
 
        const char *
        battery_state(const char *bat)
        {
-               struct {
+               static struct {
                        char *state;
                        char *symbol;
                } map[] = {
@@ -32,8 +62,11 @@
                size_t i;
                char path[PATH_MAX], state[12];
 
-               snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-                        bat, "/status");
+               if (esnprintf(path, sizeof(path),
+                             "/sys/class/power_supply/%s/status",
+                             bat) < 0) {
+                       return NULL;
+               }
                if (pscanf(path, "%12s", state) != 1) {
                        return NULL;
                }
@@ -53,21 +86,24 @@
                float timeleft;
                char path[PATH_MAX], state[12];
 
-               snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-                        bat, "/status");
+               if (esnprintf(path, sizeof(path),
+                             "/sys/class/power_supply/%s/status",
+                             bat) < 0) {
+                       return NULL;
+               }
                if (pscanf(path, "%12s", state) != 1) {
                        return NULL;
                }
 
+               if (!pick(bat, CHARGE_NOW, ENERGY_NOW, path, sizeof(path)) ||
+                   pscanf(path, "%d", &charge_now) < 0) {
+                       return NULL;
+               }
+
                if (!strcmp(state, "Discharging")) {
-                       snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-                                        bat, "/charge_now");
-                       if (pscanf(path, "%d", &charge_now) != 1) {
-                               return NULL;
-                       }
-                       snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-                                        bat, "/current_now");
-                       if (pscanf(path, "%d", &current_now) != 1) {
+                       if (!pick(bat, CURRENT_NOW, POWER_NOW, path,
+                                 sizeof(path)) ||
+                           pscanf(path, "%d", &current_now) < 0) {
                                return NULL;
                        }
 
@@ -121,8 +157,6 @@
        const char *
        battery_state(const char *unused)
        {
-               struct apm_power_info apm_info;
-               size_t i;
                struct {
                        unsigned int state;
                        char *symbol;
@@ -130,6 +164,8 @@
                        { APM_AC_ON,      "+" },
                        { APM_AC_OFF,     "-" },
                };
+               struct apm_power_info apm_info;
+               size_t i;
 
                if (load_apm_power_info(&apm_info)) {
                        for (i = 0; i < LEN(map); i++) {
@@ -150,7 +186,8 @@
 
                if (load_apm_power_info(&apm_info)) {
                        if (apm_info.ac_state != APM_AC_ON) {
-                               return bprintf("%uh %02um", apm_info.minutes_left / 60,
+                               return bprintf("%uh %02um",
+                                              apm_info.minutes_left / 60,
                                               apm_info.minutes_left % 60);
                        } else {
                                return "";