Beginner Bash Script, Need Help! Directory sizes

[opethcire]

Hello everyone, I am creating a bash script for a beginners scripting project. I need to find the sizes of all the directories and then print showing the size and the directory, but only for one level. Sample output if using the home directory:

345280 ./Desktop
11376 ./Documents
83124 ./Downloads
4 ./Music
8 ./Pictures
4 ./Public

I had a command that helped me do this :
ls -d */ | xargs du -ks

When I created my script i tried to use this, but it told me xargs was not a found command.
So far the script that I have is:

#! /bin/bash 

#Script to calculate the size of the Directories and their subdirectories in a given path 
#but only display the Directory and its size. 
# Can take in 1 argument which is a given path.  If no argument is given, Path is current directory.

case $1 in 
 '') PATH=`pwd`;;
 *) PATH=$1;; 
 esac
echo $PATH

if [ ! -d $1 ]
then
   echo $1 Not a directory, Exiting Script
   exit
fi

"side not" I tried put the ls command here.

If anyone could help me I would appreciate it greatly. I don't know if you are not allowed to use xargs in a script or if I am not putting it right.
When I tried to use just an ls command it told me that ls was not a found command. I had to use /bin/ls

[MikeTbob]

Hello and Welcome.
This is just a guess, since I suck at programming. Try using the full path to xargs, like you did with ls command.

[opethcire]

Thank you for responding. I was trying to do that, but I couldn't find where the path is. I plan to look more into this. Hopefully this is the problem since its the same error that ls was giving me.

[MikeTbob]

Locate the path with the whereis command

whereis xargs

Use the man pages also

man whereis

man xargs

[tyho]

Why don't you just use:

du --max-depth=1

It does exactly what you are trying to do with your script.

[drl]

Hi.

This appears to be homework, so I will give you a hint only. The variable name PATH is special:

       PATH   The search path for commands.  It is a colon-separated  list  of
              directories  in  which the shell looks for commands (see COMMAND
              EXECUTION below).  A zero-length (null) directory  name  in  the
              value of PATH indicates the current directory.  A null directory
              name may appear as two adjacent colons,  or  as  an  initial  or
              trailing  colon.   The  default path is system-dependent, and is
              set by the administrator who installs bash.  A common  value  is
              ``/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin''.

-- excerpt from man bash

Best wishes on your project ... cheers, drl

[opethcire]

Hello again, I was able to complete the assignment. I remembered the whereis command a little while after posting. I don't know if I should start a new thread for this or post it here, but I had two questions regarding some of the code.

All of the commands in the Bash script worked fine without their full path being written. ls, wc, du. However at the beginning of my code I have a "case ? in ?" statement. When I add this case statement to my script is when I have to start using /bin/ls, /usr/bin/wc and so on. Can anyone tell me why this is and what is happening. ?

My second question is a line in my script that I use to find if any subdirectories exist if a different directory was sent into the script as a parameter.
I use it in an if statement.
if [ ls -F -1 | grep "/" | wc -l = 0 ]
then
echo No subs
fi
I was wondering if anyone could provide an explanation of what the code is doing? I got it off the net and think I understand it.
It is using ls -F -1 to format the ls output into one column. Then it is using grep to find the ending / on the names of the directories. After that it is using wc -l to check for any newline characters and if that total is zero then there are no subdirectories.
Can anyone tell me if this is right or explain whats happening?

Thanks again in advance.