+static char *
+battery_state(const char *bat)
+{
+ char state[12];
+ FILE *fp;
+
+ ccat(3, "/sys/class/power_supply/", bat, "/status");
+ fp = fopen(concat, "r");
+ if (fp == NULL) {
+ warn("Failed to open file %s", concat);
+ return smprintf(UNKNOWN_STR);
+ }
+ fscanf(fp, "%12s", state);
+ fclose(fp);
+
+ if (strcmp(state, "Charging") == 0) {
+ return smprintf("+");
+ } else if (strcmp(state, "Discharging") == 0) {
+ return smprintf("-");
+ } else if (strcmp(state, "Full") == 0) {
+ return smprintf("=");
+ } else {
+ return smprintf("?");
+ }
+}
+