veloren/nix/utils.nix

49 lines
1.9 KiB
Nix

{ pkgs }: {
isGitLfsSetup = checkFile:
let
gitLfsCheckOutput =
builtins.readFile (pkgs.runCommand "gitLfsCheck" { } ''
([ "$(${pkgs.file}/bin/file --mime-type ${checkFile})" = "${checkFile}: image/png" ] && printf "0" || printf "1") > $out
'');
in
if gitLfsCheckOutput == "0" then
true
else
abort ''
Git Large File Storage (`git-lfs`) has not been set up correctly.
Most common reasons:
- `git-lfs` was not installed before cloning this repository.
- This repository was not cloned from the primary GitLab mirror.
- The GitHub mirror does not support LFS.
See the book at https://book.veloren.net/ for details.
Run `nix-shell -p git git-lfs --run "git lfs install --local && git lfs fetch && git lfs checkout"`
or `nix shell nixpkgs#git-lfs nixpkgs#git -c sh -c "git lfs install --local && git lfs fetch && git lfs checkout"`.
'';
# Format number of seconds in the Unix epoch as %Y-%m-%d-%H:%M.
dateTimeFormat = t:
let
rem = x: y: x - x / y * y;
days = t / 86400;
secondsInDay = rem t 86400;
hours = secondsInDay / 3600;
minutes = (rem secondsInDay 3600) / 60;
seconds = rem t 60;
# Courtesy of https://stackoverflow.com/a/32158604.
z = days + 719468;
era = (if z >= 0 then z else z - 146096) / 146097;
doe = z - era * 146097;
yoe = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365;
y = yoe + era * 400;
doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
mp = (5 * doy + 2) / 153;
d = doy - (153 * mp + 2) / 5 + 1;
m = mp + (if mp < 10 then 3 else -9);
y' = y + (if m <= 2 then 1 else 0);
pad = s: if builtins.stringLength s < 2 then "0" + s else s;
in
"${toString y'}-${pad (toString m)}-${pad (toString d)}-${pad (toString hours)}:${pad (toString minutes)}";
}