diff --git a/src/_h5ai/conf/options.json b/src/_h5ai/conf/options.json
index eb8671c6..bf281e8a 100644
--- a/src/_h5ai/conf/options.json
+++ b/src/_h5ai/conf/options.json
@@ -137,7 +137,7 @@ Options
 	Calc the size of folders.
 	*/
 	"foldersize": {
-		"enabled": false
+		"enabled": true
 	},
 
 	/*
diff --git a/src/_h5ai/server/php/inc/App.php b/src/_h5ai/server/php/inc/App.php
index a292d71d..79faeafe 100644
--- a/src/_h5ai/server/php/inc/App.php
+++ b/src/_h5ai/server/php/inc/App.php
@@ -301,19 +301,16 @@ class App {
 		}
 		$exif = function_exists("exif_thumbnail");
 		$cache = @is_writable($this->get_cache_abs_path());
-		if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
-			$tar = @preg_match("/tar(.exe)?$/i", `which tar`) > 0;
-			$zip = @preg_match("/zip(.exe)?$/i", `which zip`) > 0;
-			$convert = @preg_match("/convert(.exe)?$/i", `which convert`) > 0;
-			$ffmpeg = @preg_match("/ffmpeg(.exe)?$/i", `which ffmpeg`) > 0;
-			$du = @preg_match("/du(.exe)?$/i", `which du`) > 0;
+		if (strtoupper(substr(PHP_OS, 0, 3)) === "WIN") {
+			$cmd = "which";
 		} else {
-			$tar = @preg_match("/tar(.exe)?$/i", `command -v tar`) > 0;
-			$zip = @preg_match("/zip(.exe)?$/i", `command -v zip`) > 0;
-			$convert = @preg_match("/convert(.exe)?$/i", `command -v convert`) > 0;
-			$ffmpeg = @preg_match("/ffmpeg(.exe)?$/i", `command -v ffmpeg`) > 0;
-			$du = @preg_match("/du(.exe)?$/i", `command -v du`) > 0;
+			$cmd = "command -v";
 		}
+		$tar = @preg_match("/tar(.exe)?$/i", exec_cmd($cmd . " tar")) > 0;
+		$zip = @preg_match("/zip(.exe)?$/i", exec_cmd($cmd . " zip")) > 0;
+		$convert = @preg_match("/convert(.exe)?$/i", exec_cmd($cmd . " convert")) > 0;
+		$ffmpeg = @preg_match("/ffmpeg(.exe)?$/i", exec_cmd($cmd . " ffmpeg")) > 0;
+		$du = @preg_match("/du(.exe)?$/i", exec_cmd($cmd . " du")) > 0;
 
 		return array(
 			"idx" => $this->app_abs_href . "server/php/index.php",
diff --git a/src/_h5ai/server/php/inc/Item.php b/src/_h5ai/server/php/inc/Item.php
index 2da5bffa..cf0adaf8 100644
--- a/src/_h5ai/server/php/inc/Item.php
+++ b/src/_h5ai/server/php/inc/Item.php
@@ -58,7 +58,7 @@ class Item {
 			$options = $app->get_options();
 			if ($options["foldersize"]["enabled"]) {
 				$cmd = str_replace("[DIR]", escapeshellarg($this->abs_path), Item::$FOLDER_SIZE_CMD);
-				$this->size = intval(preg_replace("/\s.*$/", "", `$cmd`), 10) * 1024;
+				$this->size = intval(preg_replace("/\s.*$/", "", exec_cmd($cmd)), 10) * 1024;
 			}
 		} else {
 			$this->size = @filesize($this->abs_path);
diff --git a/src/_h5ai/server/php/inc/Thumb.php b/src/_h5ai/server/php/inc/Thumb.php
index c4a878f3..24efe39e 100644
--- a/src/_h5ai/server/php/inc/Thumb.php
+++ b/src/_h5ai/server/php/inc/Thumb.php
@@ -94,7 +94,7 @@ class Thumb {
 		if (!file_exists($capture_abs_path) || filemtime($source_abs_path) >= filemtime($capture_abs_path)) {
 			$cmd = str_replace("[SOURCE]", escapeshellarg($source_abs_path), $cmd);
 			$cmd = str_replace("[TARGET]", escapeshellarg($capture_abs_path), $cmd);
-			`$cmd`;
+			exec_cmd($cmd);
 		}
 
 		return file_exists($capture_abs_path) ? $capture_abs_path : null;
diff --git a/src/_h5ai/server/php/inc/util.php b/src/_h5ai/server/php/inc/util.php
index 3d679a2d..19c1ca64 100644
--- a/src/_h5ai/server/php/inc/util.php
+++ b/src/_h5ai/server/php/inc/util.php
@@ -78,7 +78,7 @@ function exec_cmd($cmd) {
 	$rc = null;
 	exec($cmd, $lines, $rc);
 
-	return $lines;
+	return implode('\n', $lines);
 }
 
 ?>
\ No newline at end of file