Added an inefficient listing for entries

src/entry.c

@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <libgen.h>
+#include <dirent.h>
 #include <sys/stat.h>
 
 bool is_entry_id_valid(const char* entry_id) {
@@ -230,6 +231,79 @@ Result remove_entry(const char* entry_id) {
 	return SUCCESS;
 }
 
+Result list_entries(char*** out_entries) {
+	*out_entries = malloc(sizeof(char*));
+	if (*out_entries == NULL) {
+		log_message(LOG_LEVEL_ERROR, "Failed to allocate memory for the entries.");
+		return OUT_OF_MEMORY;
+	}
+
+	(*out_entries)[0] = NULL;
+
+	// Open the directory
+	DIR* dir = opendir(ENTRY_POOL_DIR);
+	if (dir == NULL) {
+		log_message(LOG_LEVEL_ERROR, "Failed to open the directory '%s' (%s).", ENTRY_POOL_DIR, strerror(errno));
+		return FAILURE;
+	}
+
+	// Read the directory
+	int entry_count = 0;
+
+	struct dirent* entry;
+
+	while ((entry = readdir(dir)) != NULL) {
+		// Skip the current and parent directories
+		if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+			continue;
+
+		// Check that the entry exists
+		bool exists;
+		Result result = entry_exists(entry->d_name, &exists);
+		if (result != SUCCESS || !exists)
+			continue;
+
+		// Reallocate the entries array
+		// TODO: More efficient reallocation
+		char** new_entries = realloc(*out_entries, (entry_count + 2) * sizeof(char*));
+		if (new_entries == NULL) {
+			log_message(LOG_LEVEL_ERROR, "Failed to allocate memory for the entries.");
+			closedir(dir);
+
+			for (int i = 0; i < entry_count; i++)
+				free((*out_entries)[i]);
+			free(*out_entries);
+
+			return OUT_OF_MEMORY;
+		}
+
+		*out_entries = new_entries;
+
+		// Copy the entry name
+		(*out_entries)[entry_count] = strdup(entry->d_name);
+		if ((*out_entries)[entry_count] == NULL) {
+			log_message(LOG_LEVEL_ERROR, "Failed to allocate memory for the entry name.");
+			closedir(dir);
+
+			for (int i = 0; i < entry_count; i++)
+				free((*out_entries)[i]);
+			free(*out_entries);
+
+			return OUT_OF_MEMORY;
+		}
+
+		// Null-terminate the array
+		(*out_entries)[entry_count + 1] = NULL;
+
+		entry_count++;
+	}
+
+	// Close the directory
+	closedir(dir);
+
+	return SUCCESS;
+}
+
 Result reset_entry(const char* entry_id) {
 	// Check that it exists
 	bool exists;