build-chroot: support interpreter detection

1 files changed, 34 insertions, 4 deletions

diff --git a/build-chroot b/build-chroot
index cd608e6..dd0edee 100755
--- a/build-chroot
+++ b/build-chroot
@@ -1,6 +1,6 @@
 #!/bin/bash
 VERSION=0.1
-find_libs=~/scripts/find-libs
+find_libs=$(dirname "$(readlink -f "$0")")/find-libs
 usage() {
 	cat <<HELP
 Copies binaries and their dependencies for chroot usage.
@@ -58,6 +58,28 @@ if [ $# -eq 0 ]; then
 	exit 1
 fi
 
+resolve_interpreter() {
+	local file="$1"
+	local interp
+	interp=$(head -c 256 "$file" | awk -F '[#! \t]+' 'NR==1 && /^#!/{print $2;exit}')
+	[ -n "$interp" ] || return
+
+	echo "$interp"
+
+	# /usr/bin/env python2 -> python2
+	case "$interp" in
+	env|/usr/bin/env)
+		awk -F '[#! \t]+' '{
+			for (i=3;i<NF;i++)
+				if ($i !~ /^-/) {
+					print $i;exit
+				}
+		}'
+		;;
+	esac
+}
+
+errors=0
 subjects=()
 for subject; do
 	realsubject="$subject"
@@ -65,14 +87,22 @@ for subject; do
 	[ -e "$realsubject" ] || realsubject="$(which "$subject" 2>/dev/null)" || true
 	if [ -n "$realsubject" ]; then
 		subjects[${#subjects[@]}]="$realsubject"
+		for extra in $(resolve_interpreter "$realsubject"); do
+			if path="$(which "$extra" 2>/dev/null)"; then
+				subjects[${#subjects[@]}]="$path"
+			else
+				echo "Missing program: $extra"
+				((errors++))
+			fi
+		done
 	else
 		echo "Missing file: $subject"
+		((errors++))
 	fi
 done
 
-if ! [ $# = ${#subjects[@]} ]; then
-	echo "Some files could not be found"
-	echo "Expected $#, got ${#subjects[@]} valid args."
+if [ $errors -ne 0 ]; then
+	echo "$errors files could not be found"
 	if ! $CONT_ON_ERR; then
 		echo "Aborting. To ignore this, pass the '--continue' option."
 		exit 255