Detect batteries using glob (#163)

i3status.c

@@ -104,7 +104,7 @@ static void *scalloc(size_t size) {
     return result;
 }
 
-static char *sstrdup(const char *str) {
+char *sstrdup(const char *str) {
     char *result = strdup(str);
     exit_if_null(result, "Error: out of memory (strdup())\n");
     return result;

include/i3status.h

@@ -176,6 +176,8 @@ struct min_width {
     const char *str;
 };
 
+char *sstrdup(const char *str);
+
 /* src/general.c */
 char *skip_character(char *input, char character, int amount);
 void die(const char *fmt, ...);

src/print_battery_info.c

@@ -11,7 +11,7 @@
 
 #if defined(LINUX)
 #include <errno.h>
-#include <sys/stat.h>
+#include <glob.h>
 #include <sys/types.h>
 #endif
 
@@ -414,27 +414,23 @@ static bool slurp_all_batteries(struct battery_info *batt_info, yajl_gen json_ge
     char *outwalk = buffer;
     bool is_found = false;
 
-    /* 1,000 batteries should be enough for anyone */
-    for (int i = 0; i < 1000; i++) {
-        char batpath[1024];
-        (void)snprintf(batpath, sizeof(batpath), path, i);
+    char *placeholder;
+    char *globpath = sstrdup(path);
+    if ((placeholder = strstr(path, "%d")) != NULL) {
+        char *globplaceholder = globpath + (placeholder - path);
+        *globplaceholder = '*';
+        strcpy(globplaceholder + 1, placeholder + 2);
+    }
 
-        if (!strcmp(batpath, path)) {
+    if (!strcmp(globpath, path)) {
         OUTPUT_FULL_TEXT("no '%d' in battery path");
         return false;
     }
 
+    glob_t globbuf;
+    if (glob(globpath, 0, NULL, &globbuf) == 0) {
+        for (size_t i = 0; i < globbuf.gl_pathc; i++) {
             /* Probe to see if there is such a battery. */
-        struct stat sb;
-        if (stat(batpath, &sb) != 0) {
-            /* No such file, then we are done, assuming sysfs files have sequential numbers. */
-            if (errno == ENOENT)
-                break;
-
-            OUTPUT_FULL_TEXT(format_down);
-            return false;
-        }
-
             struct battery_info batt_buf = {
                 .full_design = 0,
                 .full_last = 0,
@@ -442,12 +438,15 @@ static bool slurp_all_batteries(struct battery_info *batt_info, yajl_gen json_ge
                 .present_rate = 0,
                 .status = CS_UNKNOWN,
             };
-        if (!slurp_battery_info(&batt_buf, json_gen, buffer, i, path, format_down))
+            if (!slurp_battery_info(&batt_buf, json_gen, buffer, i, globbuf.gl_pathv[i], format_down))
                 return false;
 
             is_found = true;
             add_battery_info(batt_info, &batt_buf);
         }
+    }
+    globfree(&globbuf);
+    free(globpath);
 
     if (!is_found) {
         OUTPUT_FULL_TEXT(format_down);