nixpkgs/pkgs/build-support/fetchhg/nix-prefetch-hg
2011-04-11 12:24:57 +00:00

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#! /bin/sh -e
url=$1
rev=$2
expHash=$3
hashType=$NIX_HASH_ALGO
if test -z "$hashType"; then
hashType=sha256
fi
if test -z "$hashFormat"; then
hashFormat=--base32
fi
if test -z "$url"; then
echo "syntax: nix-prefetch-hg URL [rev [EXPECTED-HASH]]" >&2
exit 1
fi
test -n "$rev" || rev="tip"
# If the hash was given, a file with that hash may already be in the
# store.
if test -n "$expHash"; then
finalPath=$(nix-store --print-fixed-path --recursive "$hashType" "$expHash" hg-archive)
if ! nix-store --check-validity "$finalPath" 2> /dev/null; then
finalPath=
fi
hash=$expHash
fi
# If we don't know the hash or a path with that hash doesn't exist,
# download the file and add it to the store.
if test -z "$finalPath"; then
tmpPath=/tmp/hg-checkout-tmp-$$
tmpArchive=$tmpPath/hg-archive
mkdir $tmpPath
trap "rm -rf $tmpPath" EXIT
# Perform the checkout.
if [[ $url != /* ]]; then
tmpClone=$tmpPath/hg-clone
hg clone -q -y -U "$url" $tmpClone >&2
else
tmpClone=$url
fi
hg archive -q -y -r "$rev" --cwd $tmpClone $tmpArchive
# Compute the hash.
hash=$(nix-hash --type $hashType $hashFormat $tmpArchive)
if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
# Add the downloaded file to the Nix store.
finalPath=$(nix-store --add-fixed --recursive "$hashType" $tmpArchive)
if test -n "$expHash" -a "$expHash" != "$hash"; then
echo "hash mismatch for URL \`$url'"
exit 1
fi
fi
if ! test -n "$QUIET"; then echo "path is $finalPath" >&2; fi
echo $hash
if test -n "$PRINT_PATH"; then
echo $finalPath
fi