Re: Reading hexidecimal from a file

[rikki cattermole via Digitalmars-d-learn]

On 11/09/2016 12:18 AM, Basile B. wrote:

On Saturday, 10 September 2016 at 12:12:28 UTC, Basile B. wrote:

On Saturday, 10 September 2016 at 12:04:08 UTC, Neurone wrote:

Hi,

I want to read a text file that contains sha1 hashes in hexidecimal,
then convert the hashes back into ubyte[20]. Examples of some lines:
E9785DC5  D43B5F67  F1B7D1CB  33279B7C  284E2593
04150E8F  1840BCA2  972BE1C5  2DE81039  0C486F9C

How can I do this? The documentation for format strings is pretty
dense, so couldn't understand most of it.

at compile time you can do:

import std.conv;
enum array = hexString!(import(theFile));

the run-time version was proposed
(https://github.com/dlang/phobos/pull/4487) but not interesting enough ;)

No actually, it has nothing to do with you question!

what you have to do is probably:

split join chunck(2) to!ubyte

sorry leaving now.

Actually you'd want to filter out e.g. white space as well.
So the long form via an input range would be:

struct GetHex(T) {
        string from;
        T next;
        
        this(string input) {
                from = input;
                popFront;
        }
        
        @property {
                bool empty() { return from.length == 0 || next == 0; }
                
                T front() { return next; }
        }
        
        void popFront() {
                next = 0;
                
                char[T.sizeof * 2] got;
                ubyte count;
                
                while(count < got.length && from.length > 0) {
                        got[count] = nextChar;
                        if (got[count] != 0)
                                count++;
                }

                import std.conv : parse;
                if (count > 0) {
                        char[] temp = got[0 .. count];
                        next = parse!T(temp, 16);
                }
        }
        
        char nextChar() {
                char readIn = from[0];
                from = from[1 .. $];
                
                if ((readIn >= 'A' && readIn <= 'F') || (readIn >= 'a' && readIn 
<= 'f'))
                        return readIn;
                else if (readIn >= '0' && readIn <= '9')
                        return readIn;
                else
                        return 0;
        }
}

void main() {
        string source = "
E9785DC5  D43B5F67  F1B7D1CB  33279B7C  284E2593
04150E8F  1840BCA2  972BE1C5  2DE81039  0C486F9C";
        import std.stdio : writeln;
        
        writeln(GetHex!uint(source));
}