Verify the text of a file matches a certain format

Question

I need to verify that the text of a file contains text in the following format:

#0
DIRECTION: FORWARD
SPEED: 10
TIME: 10

OR

#1
DIRECTION: REVERSE
SPEED: 10
ROTATIONS: 10

And this will repeat with multiple steps.

Where # must be followed by a number, DIRECTION must be followed by FORWARD or REVERSE, SPEED must be followed by a number and the last line will be either TIME or ROTATIONS followed by a number.

I want to verify that the file contains this text in this format and not some weird values before I start reading in the values.
Can I use some type of wild card? I have started looking at Regex, but I have not worked with it before.
What I would like to do is do some type of comparison where the number are wildcards, that way I know if the lines contain the basic formatting:

if(fileLines[0].Matches("#%")) // Where % would be the wildcard?  
if(fileLines[1].Matches("DIRECTION:%")) // Does something like this exist?

Answer 1

This patterns seems to work

    string[] lines = 
    {
        "#0",
        "DIRECTION: FORWARD",
        "SPEED: 10",
        "TIME: 10"
    };

      // meaning At start of line there is a # followed by digits till the end of line
    if(checkLine(@"^#\d+$", lines[0]) == false)
        Console.WriteLine("False on line 1");
    else
        Console.WriteLine("True on line 1");

      // meaning At start of line there is the word DIRECTION: followed by space and the words REVERSE or FORWARD
    if(checkLine(@"^DIRECTION: (REVERSE|FORWARD)", lines[1]) == false)
        Console.WriteLine("False on line 2");
    else
        Console.WriteLine("True on line 2");

      // meaning At start of line there is the word SPEED: followed by a space and digits till the end of the line
    if(checkLine(@"^SPEED: \d+$", lines[2]) == false)
        Console.WriteLine("False on line 3");
    else
        Console.WriteLine("True on line 3");

      // meaning At start of line there are the words TIME or ROTATIONS followed by colon, space and digits till the end of the line
    if(checkLine(@"^(TIME|ROTATIONS): \d+$", lines[3]) == false)
        Console.WriteLine("False on line 4");
    else
        Console.WriteLine("True on line 4");
}

// Define other methods and classes here
private bool checkLine(string regExp, string line)
{
    Regex r = new Regex(regExp);
    return r.IsMatch(line);
}

Answer 2

Provided you have read all the lines in the file as a generic list.

        List<string> fileLines = new List<string>();
        fileLines.Add("#0");
        fileLines.Add("DIRECTION: FORWARD");
        fileLines.Add("SPEED: 10");
        fileLines.Add("TIME: 10");
        fileLines.Add("#1");
        fileLines.Add("DIRECTION: REVERSE");
        fileLines.Add("SPEED: 10");
        fileLines.Add("ROTATIONS: 10");

Make use of this function to verify if the file is valid

Credit : Steve for the Regex implementation

    public bool CheckConsistancy(List<string> fileLines)
    {
        bool status = false;
        if (fileLines != null && fileLines.Count > 0)
        {
            if(fileLines.Count % 4 == 0)
            {
                List<List<string>> fileLineGroups = fileLines.Select((x, i) => new { Index = i, Value = x }).GroupBy(x => x.Index / 4).Select(x => x.Select(v => v.Value).ToList()).ToList();
                foreach (List<string> fileLineGroup in fileLineGroups)
                {
                    if (checkLine(@"^#\d", fileLineGroup[0])) 
                    {
                        if (checkLine(@"^DIRECTION: (REVERSE|FORWARD)", fileLineGroup[1]))
                        {
                            if (checkLine(@"^SPEED: \d", fileLineGroup[2]))
                            {
                                if (checkLine(@"^(TIME|ROTATIONS): \d", fileLineGroup[3]))
                                {
                                    status = true;
                                }
                                else
                                {
                                    status = false;
                                    break;
                                }
                            }
                            else
                            {
                                status = false;
                                break;
                            }
                        }
                        else
                        {
                            status = false;
                            break;
                        }
                    }
                    else
                    {
                        status = false;
                        break;
                    }
                }
            }
            else
            {
                status = false;
            }
        }
        return status;
    }

    private bool checkLine(string regExp, string line)
    {
        Regex r = new Regex(regExp);
        return r.IsMatch(line);
    } 

Call the function to check the consistancy

bool status = CheckConsistancy(fileLines);