Added usage() to jsc

esocali · Apr 1, 2020 · a3403e8 · a3403e8
1 parent 8e08a2b
commit a3403e8
Showing 1 changed file with 12 additions and 2 deletions.
diff --git a/jsc.swift b/jsc.swift
@@ -25,14 +25,24 @@ func convertCArguments(argc: Int32, argv: UnsafeMutablePointer<UnsafeMutablePoin
         args.append(arg)
 
     }
-
     return args
 }
 
+func printUsage() {
+    fputs("Usage: jsc file.js\n", thread_stdout)
+}
+
 // execute JavaScript:
 @_cdecl("jsc")
 public func jsc(argc: Int32, argv: UnsafeMutablePointer<UnsafeMutablePointer<Int8>?>?) -> Int32 {
-    guard let args = convertCArguments(argc: argc, argv: argv) else { return 0 }
+    if (argc != 2) {
+        printUsage()
+        return 0
+    }
+    guard let args = convertCArguments(argc: argc, argv: argv) else {
+        printUsage()
+        return 0
+    }
     let command = args[1]
     let fileName = FileManager().currentDirectoryPath + "/" + command
     do {