Use a minimal POSIX shar implementation for self extracting executable

This only requires POSIX shell utilies for extraction. The resulting
archive is bigger (it is not gzip compressed) and startup will be slower
due to many spawned processes.

1 files changed, 120 insertions, 0 deletions

diff --git a/shar.sh b/shar.sh
new file mode 100755
index 0000000..c7a532c
--- /dev/null
+++ b/shar.sh
@@ -0,0 +1,120 @@
+#!/bin/sh
+# Modified version of https://shiz.me/junk/code/fun/shar.sh
+# The generated shell archive is automatically extracted to a
+# temporary directory and the first archive member is executed.
+set -e
+
+if test $# -lt 2 ; then
+	echo "usage: $0 <output> <files>"
+	exit 1
+fi
+
+save() {
+	for i ; do
+		printf "%s\n" "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/"
+	done
+	echo " "
+}
+
+octal_mode() {
+	local mode
+
+	mode="$(ls -ld "$1" | awk '{ print $1 }' | tr '[A-Z]' '-' | cut -c2-)"
+	for i in 1 2 3 ; do
+		i=0
+		case "$mode" in r??*) i=$((i + 4)) ;; esac
+		case "$mode" in ?w?*) i=$((i + 2)) ;; esac
+		case "$mode" in ??-*) ;; ???*) i=$((i + 1)) ;; esac
+		printf "%d" "$i"
+		mode=$(echo "$mode" | cut -c4-)
+	done
+}
+
+out=$1
+tmpout=$1.tmp
+exe=$2
+shift
+
+rm -f "$tmpout"
+for f ; do
+	if test -f "$f" ; then
+		cat "$f" >> "$tmpout"
+	fi
+done
+trap 'rm "$tmpout"' EXIT
+
+clear=
+
+for f ; do
+	if test -z "$clear" ; then
+		set --
+		clear=1
+	fi
+
+	mode=$(octal_mode "$f")
+	if test -f "$f" ; then
+		size=$(wc -c "$f" | awk '{ print $1 }')
+		echo "adding: $f (mode $mode, $size bytes)"
+		set -- "$@" "f+$mode+$size:$f"
+	elif test -d "$f" ; then
+		echo "adding directory: $f (mode $mode)"
+		set -- "$@" "d+$mode:$f"
+	else
+		echo "can't add unknown file type $f" >&2
+	fi
+done
+
+cat >"$out"<<HEADER
+#!/bin/sh
+set -e
+
+outdir="\$(mktemp -d -p "\${TMPDIR:-/tmp}" .unshar-XXXXXX)"
+if test \$? -ne 0 -o ! -d "\$outdir" ; then
+	echo "failed to create temporary directory"
+	exit 1
+fi
+trap 'rm -rf "\$outdir"' EXIT INT QUIT TERM HUP
+argc=\$#
+
+self="\$0"
+set -- $(save "$@") "\$@"
+
+exec 3<"\$self"
+while read -r l ; do
+	test "\$l" = "exit 0;" && break
+done <&3
+
+while test \$# -gt \$argc ; do
+	file="\$1"
+	shift
+	meta="\${file%%:*}"
+	fn="\${file#*:}"
+	type="\${meta%%+*}"
+	meta="\${meta#*+}"
+	mode="\${meta%%+*}"
+	size="\${meta#*+}"
+	base="\${fn%/*}"
+
+	case "\$type" in
+	f)
+		echo "unpacking: \$fn (mode \$mode, \$size bytes)"
+		test "\$base" != "\$fn" && mkdir -p "\$outdir/\$base"
+		dd of="\$outdir/\$fn" bs="\$size" count=1 >/dev/null <&3
+		;;
+	d)
+		echo "creating: \$fn (mode \$mode)"
+		mkdir -p "\$outdir/\$fn"
+		;;
+	esac
+	chmod "\$mode" "\$outdir/\$fn" || :
+done >/dev/null 2>&1
+
+PATH="\$outdir:\$PATH" "\$outdir/$exe" "\$@"
+exit \$?
+
+exit 0;
+HEADER
+
+cat "$tmpout" >> "$out"
+chmod +x "$out"
+