syntax checks and usage output

diff --git a/mbuild.sh b/mbuild.sh
index bca4840ffab6024225028a53657ae4ed4b88a5ee..cbdd1a9efb28d84b8cf6c3b03946f73ed0a2f127 100755 (executable)
--- a/mbuild.sh
+++ b/mbuild.sh
@@ -7,7 +7,9 @@
 #
 set -eu
 
-BUILDDIR="$(mktemp -dt mbuild.XXXXXXXX)"
+ME="${0##*/}"
+
+BUILDDIR="$(mktemp -dt $ME.XXXXXXXX)"
 trap "cd / && rm -R '$BUILDDIR'" 0
 
 BUNDLE_DIR="${TMPDIR:-/tmp}"
@@ -29,12 +31,38 @@ if [ -z "$KEYID" ]; then
   exit 1
 fi
 
+DEB_BUILD_ARCH="$(dpkg-architecture -qDEB_BUILD_ARCH)"
+
+about()
+{
+  echo "$ME -- wrapper for sbuild"
+  echo "Copyright © martin f. krafft <madduck@debian.org>"
+  echo "Released under the terms of the Artistic Licence 2.0"
+}
+
+usage()
+{
+  about
+  echo
+  echo "Usage: $ME [options] [sbuild_options] file_source.changes"
+  echo
+  echo "Valid options are:"
+  cat <<-_eof | column -s\& -t
+       --dist & specify the target distribution (default: sid)
+       --arch & specify the target architecture (default: $DEB_BUILD_ARCH)
+       -h|--help & show this output.
+       -V|--version & show version information.
+       _eof
+}
+
 sbuild_args=
 schangesfile=
 arch=
 dist=
 for opt in "$@"; do
   case "$opt" in
+    -h|--help) usage; exit 0;;
+    -V|--version) about; exit 0;;
     --arch=*) arch="${opt#--arch=}";;
     --dist=*) dist="${opt#--dist=}";;
     -sa) sbuild_args="${sbuild_args:+$sbuild_args }--force-orig-source";;
@@ -59,7 +87,12 @@ for opt in "$@"; do
   esac
 done
 
-[ -z "$arch" ] && arch="$(dpkg-architecture -qDEB_BUILD_ARCH)"
+if [ -z "$schangesfile" ]; then
+  usage
+  exit 1
+fi
+
+[ -z "$arch" ] && arch="$DEB_BUILD_ARCH"
 [ -z "$dist" ] && dist="sid"
 
 schangesfile_basename="${schangesfile##*/}"