1999-07-10 Roland McGrath <roland@baalperazim.frob.com>

	* Makefile (special-targets): Add losetup.
	(SCRIPTS): Add losetup.sh.
	* losetup.sh: New file.

1 files changed, 66 insertions, 0 deletions

diff --git a/sutils/losetup.sh b/sutils/losetup.sh
new file mode 100644
index 00000000..85734571
--- /dev/null
+++ b/sutils/losetup.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+#
+# This script is roughly compatible with the Linux `losetup' utility.
+# The Hurd's `storeio' translator provides the equivalent functionality
+# (and a whole lot more), and of course works on any old file you want
+# to translate, not just magical "/dev/loopN" device files.
+#
+
+PATH=/bin
+
+usage() {
+  echo >&2 ...
+  exit 1
+}
+
+offset=0
+while [ $# -gt 0 ]; do
+  case "$arg" in
+  -d)
+    [ $# -eq 2 ] || usage
+    exec settrans -g -- "$2" /hurd/null
+    ;;
+  -e)
+    echo >&2 "$0: encryption not supported"
+    exit 3
+    ;;
+  -o)
+    [ $# -gt 1 ] || usage
+    offset="$1"
+    shift
+    ;;
+  --)
+    shift
+    break
+    ;;
+  -*)
+    usage
+    ;;
+  *)
+    break
+    ;;
+  esac
+done
+
+[ $# -eq 2 ] || usage
+device="$1"
+file="$2"
+
+# If the device name is "/dev/loopN", then create it if necessary. (?)
+create=
+case "$device" in
+'/dev/loop[0-9]*') ;; # smarty pants
+/dev/loop[0-9]*) create=--create ;;
+esac
+
+type='-Tfile '
+if [ "$offset" != 0 ]; then
+  blksz=`storeinfo -B -- "$file"`
+  if [ $[ $offset % $blksz ] -ne 0 ]; then
+    echo >&2 "$0: offset $offset is not a multiple of device block size $blksz"
+    exit 1
+  fi
+  type="-Tremap $[ $offset / $blksz ]+:file:"
+fi
+
+exec settrans $create -gap -- "${device}" /hurd/storeio ${type}"${file}"