Linux bash script to copy directory and sub directories - copy

Question

I want to copy all the files and sub directories from a directory to a different directory. However I only want to copy them if they are not already in the destination directory or if the timestamp on the source directory file is newer than the timestamp on the destination directory. I am having troubles getting into all of the sub directories. I am able to get down one level but not the next. For example, with directory /a/b/c, I am able to get to sub directory b but not to c. The only way I could see doing this was with a recursive function. My code is below.
#!/bin/bash
SOURCEDIR=/home/kyle/Smaug/csis252
DESTDIR=/home/kyle/Desktop/csis252
copy() {
local DIRECTORY=$1
for FILE in `ls $DIRECTORY`
do
if [ -f $DIRECTORY/$FILE ]
then
echo $FILE file
cp $DIRECTORY/$FILE $DESTDIR/$DIRECTORY/$FILE
fi
if [ -d $FILE ]
then
echo $FILE directory
mkdir $DESTDIR/$DIRECTORY/$FILE
copy $DIRECTORY/$FILE
fi
done
}
cd $SOURCEDIR
copy .
I forgot the $DIRECTORY in the second if statement. I feel stupid now but sometimes it just takes someone else to read through to find stuff like this. I did not use the cp -r $SOURCEDIR $DESTDIR because this would copy everything and sometimes I do not want that. I tried the cp -ur $SOURCEDIR $DESTDIR but it would only copy new stuff over, not update the existing stuff. The final version of my code is below.
#!/bin/bash
SOURCEDIR=/home/kyle/Smaug/csis252
DESTDIR=/home/kyle/Desktop/csis252
copy() {
local DIRECTORY=$1
for FILE in `ls $DIRECTORY`
do
if [ ! -f $DESTDIR/$DIRECTORY/$FILE ] && [ ! -d $DESTDIR/$DIRECTORY/$FILE ]
then
if [ -f $DIRECTORY/$FILE ]
then
echo "$DIRECTORY/$FILE copied"
cp $DIRECTORY/$FILE $DESTDIR/$DIRECTORY/$FILE
fi
if [ -d $DIRECTORY/$FILE ]
then
echo "$DIRECTORY/$FILE directory made"
mkdir $DESTDIR/$DIRECTORY/$FILE
copy $DIRECTORY/$FILE
fi
else
if [ $DESTDIR/$DIRECTORY/$FILE -nt $DIRECTORY/$FILE ] && [ ! -d $DIRECTORY/$FILE ]
then
cp $DIRECTORY/$FILE $DESTDIR/$DIRECTORY/$FILE
echo "$DIRECTORY/$FILE updated"
fi
fi
done
}
cd $SOURCEDIR
copy .

Answer 1

Simpler would be
cp -ur $SOURCEDIR $DESTDIR
-r recursivly copies folders and subfolders
-u updates, copies only when the source is newer

Answer 2

if [ -f $DIRECTORY/$FILE ]
...
if [ -d $FILE ]
You forgot $DIRECTORY/ in your -d check. This isn't a problem for the top-level directories, because when DIRECTORY is ., [ -d dir ] and [ -d ./dir ] will always give the same result, but for subdirectories it does matter.
Note: you may want to look at pre-written programs that do this. cp (at least the GNU version) or rsync can probably avoid the need for any custom script, and also handle special files (special file name characters, or special file types) better than any script will.