Adding egrep hook; better iteration for whitespace; improving local tests

Hooks/pre-commit

@@ -9,6 +9,7 @@
 
 # Run all our checking scripts.
 for script in $(find `dirname "$0"`/scripts.d -type f); do
+    echo "Running ${script}"
     "$script"
     if [ $? -ne 0 ]; then
         echo "$script" failed checks.

Hooks/scripts.d/egrep

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+if git ls-files | xargs --delimiter='\n' grep -irlE 'egrep' | grep -v 'Hooks/scripts.d/egrep' ; then
+    echo 'Egrep has been deprecated as of GNU grep 3.8 -- replace `egrep` with `grep -E`.'
+    echo https://www.gnu.org/software/grep/manual/grep.html
+    exit 1
+fi

Hooks/scripts.d/local-hooks

@@ -1,8 +1,11 @@
+#!/bin/bash
 # This script ensures that repos can commit personal hooks in the ./precommit-hooks folder.
 
-for script in `find precommit-hooks -type f`; do
-    if ! bash "$script"; then
-        echo "Local script $script failed checks."
-        exit 1
-    fi
-done
+if [ -d precommit-hooks ]; then
+    for script in `find precommit-hooks -type f`; do
+        if ! bash "$script"; then
+            echo "Local script $script failed checks."
+            exit 1
+        fi
+    done
+fi

Hooks/scripts.d/whitespace

@@ -2,13 +2,12 @@
 
 # Sourced from https://github.com/git/git/blob/master/templates/hooks--pre-commit.sample
 
-if git ls-files | xargs egrep -irl '\s\+$' ; then
+if git ls-files | xargs --delimiter='\n' grep -irlE '\s\+$'; then
     echo The above lines have trailing whitespace. Run "sed -i 's/\s\+$//'" on the affected files.
     exit 1
 fi
 
-if git rev-parse --verify HEAD >/dev/null 2>&1
-then
+if git rev-parse --verify HEAD >/dev/null 2>&1; then
 	against=HEAD
 else
 	# Initial commit: diff against an empty tree object