diff --git a/Sources/FengNiao/main.swift b/Sources/FengNiao/main.swift
index 242458d..fd02f69 100644
--- a/Sources/FengNiao/main.swift
+++ b/Sources/FengNiao/main.swift
@@ -36,6 +36,8 @@ let EX_OK: Int32 = 0
 let EX_USAGE: Int32 = 64
 #endif
 
+let EXIT_UNUSED_RESOURCES: Int32 = 1
+
 let cli = CommandLineKit.CommandLine()
 cli.formatOutput = { s, type in
     var str: String
@@ -79,6 +81,9 @@ let skipProjRefereceCleanOption = BoolOption(
 )
 cli.addOption(skipProjRefereceCleanOption)
 
+let xcodeWarningsOption = BoolOption(longFlag: "xcode-warnings", helpMessage: "Print results as xcode warnings and return non zero code if any.")
+cli.addOption(xcodeWarningsOption)
+
 let versionOption = BoolOption(longFlag: "version", helpMessage: "Print version.")
 cli.addOption(versionOption)
 
@@ -144,6 +149,14 @@ if unusedFiles.isEmpty {
     exit(EX_OK)
 }
 
+if xcodeWarningsOption.value {
+    for file in unusedFiles.sorted(by: { $0.size > $1.size }) {
+        print("\(file.path.string): warning: Unused resource of size \(file.readableSize)")
+    }
+
+    exit(EXIT_UNUSED_RESOURCES);
+}
+
 if !isForce {
     var result = promptResult(files: unusedFiles)
     while result == .list {