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I am trying to execute or run a file in Ubuntu, by using ./filename on the command line. When I try and run it, I get this error:

Error: A mode argument is required

There is no file extension on the file. The file is called oracle and as far as I know, there shouldn't be a problem with the file.

How do I fix the error and run the file?

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The file your are trying to start requires AT LEAST 1 ARGUMENT.

As you can see here the method used here is oracle callgraph <package> and the code in the software has your message:

args := flag.Args()
+ if len(args) == 0 || args[0] == "" {
+ fmt.Fprint(os.Stderr, "Error: a mode argument is required.\n"+useHelp)
+ os.Exit(2)

It will exit the program with that error message if the amount of arguments is zero or is it is empty.

If your filename is filename I expect it needs to be at least

oracle filename
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