clang

unvendor

06/download.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+
+# Receives files as arguments, scans them for lines like
+# #> FETCH dd16fb1d67bfab79a72f5e8390735c49e3e8e70b4945a15ab1f81ddb78658fb3
+# #>  FROM http://ftp.gnu.org/gnu/make/make-4.4.1.tar.gz
+# #>    AS make.tar.gz
+# or
+#   #local = "/downloads/make.tar.gz";
+#   url = "http://ftp.gnu.org/gnu/make/make-4.4.1.tar.gz";
+#   sha256 = "dd16fb1d67bfab79a72f5e8390735c49e3e8e70b4945a15ab1f81ddb78658fb3";
+# downloads to ./downloads if file's not present there yet, verifies hash,
+# copies file over to $DESTDIR.
+
+set -ue
+
+: ${DESTDIR:=stage/downloads}  # final location of putting the file
+: ${ONLY:=all}  # allow to limit to just a single file
+mkdir -p downloads   # first cached there, so that stage can be cleaned freely
+
+fetch() {
+	hash=$1; url=$2; filename=${3:-$(basename "$url")}
+	if [[ -e "downloads/$filename" ]]; then
+		pushd downloads >/dev/null
+			echo "$hash $filename" | sha256sum -c
+		popd >/dev/null
+	else
+		mkdir -p downloads/.tmp$$
+		pushd downloads/.tmp$$ >/dev/null
+			wget -nv --show-progress "$url" -O "$filename"
+			echo "$hash $filename" | sha256sum -c --quiet
+		popd >/dev/null
+		mv "downloads/.tmp$$/$filename" downloads/
+		rm -d downloads/.tmp$$
+	fi
+	if [[ "${DESTDIR:-}" != downloads ]]; then
+		mkdir -p "$DESTDIR"
+		cp -a --reflink=auto "downloads/$filename" \
+			"$DESTDIR/$filename"
+	fi
+}
+
+REGEX_MAGIC='^#> '
+REGEX_FETCH='^#> FETCH'
+REGEX_FROM='^#>  FROM'
+REGEX_AS='^#>    AS'
+NIX_REGEX_FETCH='^[[:blank:]]*sha256[[:blank:]]*=[[:blank:]]*"(.*)";$'
+NIX_REGEX_FROM='^[[:blank:]]*url[[:blank:]]*=[[:blank:]]*"(.*)";$'
+NIX_REGEX_AS='^[[:blank:]]*#[[:blank:]]local[[:blank:]]*=[[:blank:]]*/downloads/(.*);$'
+process_commands_in() {
+	hash=''; url=''; filename=''
+	while read -r line; do
+		if [[ "$line" =~ $REGEX_MAGIC ]]; then
+			if [[ "$line" =~ $REGEX_FETCH ]]; then
+				hash="${line##"#> FETCH"}"
+			elif [[ "$line" =~ $REGEX_FROM ]]; then
+				url="${line##'#>  FROM '}"
+			elif [[ "$line" =~ $REGEX_AS ]]; then
+				filename="${line##'#>    AS '}"
+			else
+				echo "### $0: malformed line '$line' in '$1'"
+				exit 2
+			fi
+		elif [[ "$line" =~ $NIX_REGEX_FETCH ]]; then
+		     hash=${BASH_REMATCH[1]}
+		elif [[ "$line" =~ $NIX_REGEX_FROM ]]; then
+		     url=${BASH_REMATCH[1]}
+		elif [[ "$line" =~ $NIX_REGEX_AS ]]; then
+			filename=${BASH_REMATCH[1]}
+		else
+			if [[ -n "$hash" && -n "$url" ]]; then
+				filename=${filename:-$(basename $url)}
+				if [[ "$ONLY" == all || \
+						"$ONLY" == "$filename" ]]; then
+					fetch "$hash" "$url" "$filename"
+				fi
+			fi
+			hash=''; url=''; filename=''
+		fi
+	done < $1
+}
+
+[[ $# == 0 ]] && files='recipes/*.sh recipes/*/*.sh' || files="$@"
+for f in $files; do
+	process_commands_in $f
+done