Utility that converts FEN+move -> new FEN

[titanD]

Would there happen to exist a tool (or a better way) that could get me from a FEN + a move to an updated FEN?

I was also thinking maybe just something that converts a PGN to an array of FEN's.

Then I could just turn the FEN + move into an array with starting position = FEN and a move list with the one move. Array would then be two FEN's, the last of which I wanted.

[Ferdy]

Would there happen to exist a tool (or a better way) that could get me from a FEN + a move to an updated FEN?

I can't understand that, describe more, give an example.

Let me think from your added description.

I was also thinking maybe just something that converts a PGN to an array of FEN's.

There is a tool called pgn2fen. This tool can also turn pgn to epd.

Then I could just turn the FEN + move into an array with starting position = FEN and a move list with the one move. Array would then be two FEN's, the last of which I wanted.

I can't understand this.

[Evert]

Would there happen to exist a tool (or a better way) that could get me from a FEN + a move to an updated FEN?

Sjaakii can do this easily if you're willing to run it on its own (for instance in a terminal).
Given this input:

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xboard

force setboard rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -
e4
fen

it produces the output

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rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1

To get that directly from the command line, you'd run

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$sjaakii < fenmove2fen.in | tail -n1

where "fenmove2fen.in" contains the input I mentioned above.

One comment: as you can see from the FEN, Sjaakii sets the en-passant field "e3", even if the en-passant capture isn't actually legal. Strictly speaking this violates the FEN specification, but this ought to be harmless.

[hgm]

It all depends in which format you have the FEN + move. The standard format for storing moves is of course PGN. If you would have a file with such 1-move games, you could use it as a list of opening lines in WinBoard, for playing a match between two Resign engines (which resign as soon as they have to think up a move), and set WinBoard to save the final position of each game to a file.

The minimal requirement so that WinBoard still recognizes the input as a PGN game would be the FEN tag plus a move. Like

[FEN "1k6/7R/1K6/8/8/8/8/8 w - - 0 1"] h7h8

I am not sure I included the Resign engine in the WinBoard install, however. (I use it myself to extract starting positions from opening books.)