Recursive Function to Return Directory Depth - linux

Question

I'm trying to write recursive scripts in bash that receive as an argument a single path and prints the depth of the directory tree rooted at this path.
This is the list_dirs.sh script:
ls -l $dir | grep dr..r..r.. | sed 's/.*:...\(.*\)/\1/'
And this is the isdir.sh script:
if [ -d $1 ]; then
echo 1
elif [ -e $1 ]; then
echo 0
else
echo -1
fi
They both work good.
This is the script dir_depth.sh that I wrote that doesn't work:
if [ $# -eq 0 ]; then
echo "Usage: ./dir_depth.sh <path>"
exit1
fi
x=`source isdir.sh $1`
if [ $x -eq -1 ]; then
echo "no such path $1"
fi
dir=$1
maxD=0
dirs=`source list_dirs.sh`
for f in $dirs
do
if [ $x -ne 0 ]; then
x=`dir_depth.sh $f`
if [ "$x" -eq "$maxD" ]; then
maxD=x;
fi
fi
echo $f
done
echo $((maxD++))
I'm really new to bash scripting and I don't know how to debug or what's wrong in my script.

Answer 1

Some missing items are:
If you have a directory parent/child/ and run list_dirs.sh parent/, it will output child. You then try to look up child/ in the current directory instead of parent/child/.
You do echo $f for debug purposes and echo $((maxD++)) to return a result. They are being confused for each other. Use >&2 to write errors and debug messages to stderr.
echo $((maxD++)) is a classic error equivalent to return x++. You return the number, and then increment a variable that's no longer used.
[ "$x" -eq "$maxD" ] makes no sense. Use -ge since you're trying to find the max.
Here's dir_depth.sh with these changes in place:
if [ $# -eq 0 ]; then
echo "Usage: ./dir_depth.sh <path>" >&2
exit 1
fi
x=`source ./isdir.sh $1`
if [ $x -eq -1 ]; then
echo "no such path $1" >&2
fi
dir=$1
dirs=`source ./list_dirs.sh`
maxD=0
for f in $dirs
do
if [ $x -ne 0 ]; then
x=`./dir_depth.sh "$1/$f"`
if [ "$x" -ge "$maxD" ]; then
maxD="$x";
fi
fi
echo $f >&2
done
echo $((maxD+1))