Ygtjki

All,I used following piece of code to list down the contents of a directory in macOS:

#!/bin/bash

echo "hello User"
echo ""
userdir=$1
var_one=$userdir/Library/Application Support/iCloud/Accounts/
 if [ -d "$var_one" ]
 then
 # echo "Direcotry exists"
 echo "The AppleID is : "
 sed -n '/[*w-]+@([w-]+.)+[w-]+/p'|ls "$var_one"|awk NR==2'print'
 echo "~~~~~~~BYE~~~~~~" 
 break
 else
 echo "Directory doesn't exists" 
 echo "The path is $var_one"
 fi 

If the directory exists then sed command is used along with regex pattern to identify the desired file. The script works fine but doesn't seem to exit. I am new to this and might be missing out important bits & pieces. Any suggestions/codes for further improvement are welcome.

Try replacing:

sed -n '/[*w-]+@([w-]+.)+[w-]+/p'|ls "$var_one"|awk NR==2'print'

With something like this:

ls "$var_one" | sed -n '2/[*w-]+@([w-]+.)+[w-]+/p'

See also: Why not parse ls (and what do to instead)?

There's a few things that could be improved in your script.

First of all, the sed doesn't do anything because it's not receiving any input. This means that it will just sit there waiting for you to type things on the keyboard into its standard input stream. Additionally, don't use sed or other text editing tools (awk etc.) on filenames. Filenames on Unix systems can, contain newlines, and sed (for example) reads individual lines, which means it would read a filename with an embedded newline as two separate things.

It's uncommon for filenames to contain newlines, but if a script don't take this into account, a malicious user may possibly use this fact to confuse the script into doing things it wasn't designed to do.

To find the currently signed in Apple ID, rather than using some heuristic approach, use a tool that can do it for you. With Homebrew, you may install mas:

brew install mas

Then,

mas account

will give you the currently signed in Apple ID.