Realization:

• 1. Use the sys.argv function to obtain the parameters input from the command line for passing parameters

  if len(sys.argv) !=3: # Tips for using 3 output commands if the number of parameters is not
      print('''
      usage:  {} file1 file2 [>] [file to save]
      '''.format(sys.argv[0]))
  else: # When the input parameters meet the requirements for comparison
      ... ...

• 2. Use the difflib.Htmldiff function to compare, and output the html page source code with strong readability

#The last two parameters of sys.argv are the file names to be compared
file1 = sys.argv[1]
file2 = sys.argv[2]
try:
        with open(file1)as f1 ,open(file2)as f2: # Open two files
                content1= f1.read().splitlines(keepends=True) # Read the file
                content2= f2.read().splitlines(keepends=True)
                diff = difflib.HtmlDiff() # Create a tool object
                result =diff.make_file(content1,content2) # Get file comparison results
                print(result) # Output results, you can see the source code written in html
except Exception as e: # Abnormal output prompt
        print('Error:'+e)

• 3. Indicate the interpreter location and coding format at the beginning of the document

  #!/usr/local/python3/bin/python3.6
  #encoding=utf-8

  Full code:

  #!/usr/local/python3/bin/python3.6
  #encoding=utf-8
  import sys
  import difflib
  if len(sys.argv) !=3: # Tips for using 3 output commands if the number of parameters is not
      print('''
      usage:  {} file1 file2 [>] [file to save]
      '''.format(sys.argv[0]))
  else: # When the input parameters meet the requirements for comparison
      file1 = sys.argv[1]
      file2 = sys.argv[2]
      try:
              with open(file1)as f1, open(file2)as f2:  # Open two files
                      content1 = f1.read().splitlines(keepends=True)  # Read the file
                      content2 = f2.read().splitlines(keepends=True)
                      diff = difflib.HtmlDiff()  # Create a tool object
                      result = diff.make_file(content1, content2)  # Get file comparison results
                      print(result)  # Output results, you can see the source code written in html
      except Exception as e:  # Abnormal output prompt
              print('Error:' + e)

• 4. Copy the py file to / usr/local/bin / (this path is already in the environment variable), and increase the execution permission. At this time, you can see the mydiff command by using the tab key to complete
  

• 5. Test command, output an html code
  

• 6. Redirect to generate an HTML file on the desktop (mydiff / etc / passwd / TMP / paswd > / home / kiosk / desktop / diff.html)
  

• 7. Open it with a browser, and you can see the html page with strong readability