fix and dedup code

test does not understand shell subcommand syntax

Author: infeo

src/main/java/org/cryptomator/linux/quickaccess/DolphinPlaces.java

@@ -6,6 +6,7 @@
 import org.cryptomator.integrations.common.Priority;
 import org.cryptomator.integrations.quickaccess.QuickAccessService;
 import org.cryptomator.integrations.quickaccess.QuickAccessServiceException;
+import org.cryptomator.linux.util.SupportUtil;
 import org.xml.sax.SAXException;
 
 import javax.xml.XMLConstants;
@@ -160,14 +161,6 @@ private int indexOfEntryOpeningTag(String placesContent, int idIndex) {
 
 	@CheckAvailability
 	public static boolean isSupported() {
-		try {
-			var nautilusExistsProc = new ProcessBuilder().command("test", "`command -v dolphin`").start();
-			if (nautilusExistsProc.waitFor(5000, TimeUnit.MILLISECONDS)) {
-				return nautilusExistsProc.exitValue() == 0;
-			}
-		} catch (IOException | InterruptedException e) {
-			//NO-OP
-		}
-		return false;
+		return SupportUtil.commandExists("dolphin");
 	}
 }

src/main/java/org/cryptomator/linux/quickaccess/NautilusBookmarks.java

@@ -6,6 +6,7 @@
 import org.cryptomator.integrations.common.Priority;
 import org.cryptomator.integrations.quickaccess.QuickAccessService;
 import org.cryptomator.integrations.quickaccess.QuickAccessServiceException;
+import org.cryptomator.linux.util.SupportUtil;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -84,14 +85,6 @@ public void remove() throws QuickAccessServiceException {
 
 	@CheckAvailability
 	public static boolean isSupported() {
-		try {
-			var nautilusExistsProc = new ProcessBuilder().command("test", "`command -v nautilus`").start();
-			if (nautilusExistsProc.waitFor(5000, TimeUnit.MILLISECONDS)) {
-				return nautilusExistsProc.exitValue() == 0;
-			}
-		} catch (IOException | InterruptedException e) {
-			//NO-OP
-		}
-		return false;
+		return SupportUtil.commandExists("nautilus");
 	}
 }

src/main/java/org/cryptomator/linux/util/SupportUtil.java

@@ -0,0 +1,21 @@
+package org.cryptomator.linux.util;
+
+import java.io.IOException;
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+
+public class SupportUtil {
+
+	public static boolean commandExists(String commandName) {
+		var shell = Objects.requireNonNullElse(System.getenv("SHELL"),"sh");
+		try {
+			var cmdExistsProcess = new ProcessBuilder().command(shell, "-c", "command -v " + commandName).start();
+			if (cmdExistsProcess.waitFor(5000, TimeUnit.MILLISECONDS)) {
+				return cmdExistsProcess.exitValue() == 0;
+			}
+		} catch (IOException | InterruptedException e) {
+			//NO-OP
+		}
+		return false;
+	}
+}