Upgrade wordpress to latest version

wp-upgrade.sh

#!/bin/bash
NOW=`date +%Y%m%d%H%M%S`
if [ -z "$1" ]; then
  echo "Usage: $0 <source-zip>|<source-dir> <target-dir>"
  exit 1
fi
if [ -z "$2" ]; then
  wget "http://wordpress.org/latest.zip" -O "wordpress-$NOW.zip"
  src="wordpress-$NOW.zip"
  target=$1
elif [[ $1 =~ https?://.* ]]; then
  wget "$1"
  src=`basename $1`
  target=$2
else
  if [ ! -f "$1" -a "$1" == "wordpress-*.zip" ]; then
    wget "https://downloads.wordpress.org/release/$1"
    src=`basename $1`
    target=$2
  else
    src=$1
    target=$2
  fi
fi
if [ -f "$src" ]; then
  mkdir "wp-temp-$NOW"
  if [ $? != 0 ]; then
    echo echo "Unable to extract from zipfile '$src'"
    exit 1
  fi
  unzip -q "$src" -d "wp-temp-$NOW"
  if [ $? != 0 ]; then
    rm -r "wp-temp-$NOW"
    echo "Unable to extract from zipfile '$src'"
    exit 1
  fi
  SOURCE="wp-temp-$NOW/wordpress"
else
  SOURCE="$src"
fi
if [ ! -d "$SOURCE" ]; then
  echo "Source '$src' does not exist or is not a file or directory"
  exit 1
fi
TARGET="$target"
if [ ! -d "$TARGET" ]; then
  echo "Target '$TARGET' does not exist or is not a directory"
  exit 1
fi
if [ -d "$TARGET/wp-includes" ]; then
  echo "Copying new wp-includes - old contents will be moved to $TARGET/wp-includes-$NOW"
  mv "$TARGET/wp-includes" "$TARGET/wp-includes-$NOW" && cp -pr "$SOURCE/wp-includes" "$TARGET"
else
  cp -pr "$SOURCE/wp-includes" "$TARGET"
fi
if [ -d "$TARGET/wp-admin" ]; then
  echo "Copying new wp-admin - old contents will be moved to $TARGET/wp-admin-$NOW"
  mv "$TARGET/wp-admin" "$TARGET/wp-admin-$NOW" && cp -pr "$SOURCE/wp-admin" "$TARGET"
else
  cp -pr "$SOURCE/wp-admin" "$TARGET"
fi
for f in `ls "$SOURCE"`; do
  if [ -f "$SOURCE/$f" ]; then
    echo "Copying $f"
    cp "$SOURCE/$f" "$TARGET"
  fi
done
echo "Cleaning up"
if [ -d "wp-temp-$NOW" ]; then
  rm -r "wp-temp-$NOW"
fi
if [ -f "wordpress-$NOW.zip" ]; then
  rm "wordpress-$NOW.zip"
fi
echo "Done"