Read fixed width record from text file

Question

I've got a text file full of records where each field in each record is a fixed width. My first approach would be to parse each record simply using string.Substring(). Is there a better way?

For example, the format could be described as:

<Field1(8)><Field2(16)><Field3(12)>

And an example file with two records could look like:

SomeData0000000000123456SomeMoreData
Data2   0000000000555555MoreData    

I just want to make sure I'm not overlooking a more elegant way than Substring().

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Update: I ultimately went with a regex like Killersponge suggested:

private readonly Regex reLot = new Regex(REGEX_LOT, RegexOptions.Compiled);
const string REGEX_LOT = "^(?<Field1>.{6})" +
                        "(?<Field2>.{16})" +
                        "(?<Field3>.{12})";

I then use the following to access the fields:

Match match = reLot.Match(record);
string field1 = match.Groups["Field1"].Value;

Answer 1

Substring sounds good to me. The only downside I can immediately think of is that it means copying the data each time, but I wouldn't worry about that until you prove it's a bottleneck. Substring is simple :)

You could use a regex to match a whole record at a time and capture the fields, but I think that would be overkill.