validate input file format in dxt_analyzer

darshan-util/dxt_analyzer.py

@@ -80,6 +80,7 @@ import matplotlib
 import matplotlib.pyplot as plt
 import re
 import argparse
+import sys
 
 #------------------------------------------------------------------------------
 # Regular expression and helper funtion definitions
@@ -258,6 +259,14 @@ if (args.singlefile_mode):
     
 
 with open(dxt_logname) as infile:
+    try:
+        line = infile.readline()
+        if "# darshan" not in line:
+            raise Exception('Invalid file format')
+    except:
+        print("Error: unable to parse " + dxt_logname + ".", file=sys.stderr)
+        print("   Please make sure that it was generated by the darshan-dxt-parser utility.", file=sys.stderr)
+        sys.exit(1)
     finfo_dict = {}
     curr_fname = ''
     logdata = []