misc: add whitespace removal tool

Also-by: Alejandro Gomez <Alejandro.Gomez@data61.csiro.au>

misc/whitespace/fix-commit-whitespace

@@ -0,0 +1,59 @@
+#!/bin/bash
+#
+# Copyright 2017, Data61
+#
+# This software may be distributed and modified according to the terms of
+# the BSD 2-Clause license. Note that NO WARRANTY is provided.
+# See "LICENSE_BSD2.txt" for details.
+#
+# @TAG(DATA61_BSD)
+#
+
+
+DIFF_COMMAND="git diff"
+REF=HEAD
+
+
+case ${1} in
+    index) DIFF_COMMAND="git diff-index"
+           ;;
+    help|-h|--help) cat <<EOF
+usage: tws_rm [index|help] [ref]
+  index : use changes in the index
+  help  : this message
+  ref   : compare against ref (Default: HEAD)
+EOF
+                    exit 0
+                    ;;
+    *) if git rev-parse --verify -q ${1-HEAD} > /dev/null
+       then REF=${1-HEAD}
+       else echo "[ERROR] ${1} is not a valid reference"
+            exit 1
+       fi
+       ;;
+esac
+
+[ "${REF}" = "HEAD" ] && [ ! -z $2 ] && REF=${2}
+if ! git rev-parse --verify -q ${REF} > /dev/null
+then echo "[ERROR] ${REF} is not a valid reference"
+     exit 1
+fi
+
+if [ ! -d .git/ ] || ! git rev-parse --git-dir > /dev/null
+then echo "[ERROR] this is supposed to be run in a git repo"
+     exit 1
+fi
+
+if [ `uname` == "Darwin" ]; then
+    SED="/usr/bin/sed -i ''"
+else
+    SED="sed -i"
+fi
+
+for TWS in $(${DIFF_COMMAND} --check ${REF} | grep "trailing whitespace" | cut -d: -f1-2)
+do
+    FILE=$(echo ${TWS} | cut -d: -f1)
+    LINE=$(echo ${TWS} | cut -d: -f2)
+
+    $SED ${LINE}'s/[ \t]*$//' $FILE
+done