diff --git a/mkconcore.py b/mkconcore.py
index 3b20f8e4..8999b8fd 100644
--- a/mkconcore.py
+++ b/mkconcore.py
@@ -75,40 +75,45 @@
 import shlex  # Added for POSIX shell escaping
 
 # input validation helper
-def safe_name(value, context, allow_path=False):
-    """
-    Validates that the input string does not contain characters dangerous 
-    for filesystem paths or shell command injection.
-    """
-    if not value:
-        raise ValueError(f"{context} cannot be empty")
-    # blocks control characters and shell metacharacters
-    # allow path separators and drive colons for full paths when needed
-    if allow_path:
-        pattern = r'[\x00-\x1F\x7F*?"<>|;&`$\'()]'
-    else:
-        # blocks path traversal (/, \, :) in addition to shell metacharacters
-        pattern = r'[\x00-\x1F\x7F\\/:*?"<>|;&`$\'()]'
-    if re.search(pattern, value):
-        raise ValueError(f"Unsafe {context}: '{value}' contains illegal characters.")
-    return value
-
-MKCONCORE_VER = "22-09-18"
-
-SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
-
-def _resolve_concore_path():
-    script_concore = os.path.join(SCRIPT_DIR, "concore.py")
-    if os.path.exists(script_concore):
-        return SCRIPT_DIR
-    cwd_concore = os.path.join(os.getcwd(), "concore.py")
-    if os.path.exists(cwd_concore):
-        return os.getcwd()
-    return SCRIPT_DIR
-
-GRAPHML_FILE = sys.argv[1]
-TRIMMED_LOGS = True
-CONCOREPATH = _resolve_concore_path()
+def safe_name(value, context, allow_path=False):
+    """
+    Validates that the input string does not contain characters dangerous 
+    for filesystem paths or shell command injection.
+    """
+    if not value:
+        raise ValueError(f"{context} cannot be empty")
+    # blocks control characters and shell metacharacters
+    # allow path separators and drive colons for full paths when needed
+    if allow_path:
+        pattern = r'[\x00-\x1F\x7F*?"<>|;&`$\'()]'
+    else:
+        # blocks path traversal (/, \, :) in addition to shell metacharacters
+        pattern = r'[\x00-\x1F\x7F\\/:*?"<>|;&`$\'()]'
+    if re.search(pattern, value):
+        raise ValueError(f"Unsafe {context}: '{value}' contains illegal characters.")
+    return value
+
+MKCONCORE_VER = "22-09-18"
+
+SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
+
+def _resolve_concore_path():
+    script_concore = os.path.join(SCRIPT_DIR, "concore.py")
+    if os.path.exists(script_concore):
+        return SCRIPT_DIR
+    cwd_concore = os.path.join(os.getcwd(), "concore.py")
+    if os.path.exists(cwd_concore):
+        return os.getcwd()
+    return SCRIPT_DIR
+
+if len(sys.argv) < 4:
+    logging.error("Usage: python mkconcore.py <GRAPHML_FILE> <sourcedir> <outdir> [type]")
+    logging.error(" type must be posix (macos or ubuntu), windows, or docker")
+    quit()
+
+GRAPHML_FILE = safe_name(sys.argv[1], "GRAPHML file argument", allow_path=True)
+TRIMMED_LOGS = True
+CONCOREPATH = _resolve_concore_path()
 CPPWIN    = "g++"        #Windows C++  6/22/21
 CPPEXE    = "g++"        #Ubuntu/macOS C++  6/22/21
 VWIN      = "iverilog"   #Windows verilog  6/25/21
@@ -152,18 +157,15 @@ def _resolve_concore_path():
 sourcedir = sys.argv[2]
 outdir = sys.argv[3]
 
-# Validate outdir argument (allow full paths)
-safe_name(outdir, "Output directory argument", allow_path=True)
+# Validate arguments (allow full paths)
+safe_name(sourcedir, "Source directory argument", allow_path=True)
+safe_name(outdir, "Output directory argument", allow_path=True)
 
 if not os.path.isdir(sourcedir):
     logging.error(f"{sourcedir} does not exist")
     quit()
 
-if len(sys.argv) < 4:
-    logging.error("usage: py mkconcore.py file.graphml sourcedir outdir [type]")
-    logging.error(" type must be posix (macos or ubuntu), windows, or docker")
-    quit()
-elif len(sys.argv) == 4:
+if len(sys.argv) == 4:
     prefixedgenode = outdir+"_" #nodes and edges prefixed with outdir_ only in case no type specified 3/24/21
     concoretype = "docker"
 else:
@@ -1227,4 +1229,4 @@ def cleanup_script_files():
     os.chmod(outdir+"/clear",stat.S_IRWXU) 
     os.chmod(outdir+"/maxtime",stat.S_IRWXU) 
     os.chmod(outdir+"/params",stat.S_IRWXU) 
-    os.chmod(outdir+"/unlock",stat.S_IRWXU)
+    os.chmod(outdir+"/unlock",stat.S_IRWXU)