exit command doesn't work in bash [duplicate]

I think you'll probably find that, in someErrorProgram || (exit 0), the exit 0 is being run in a sub-shell due to the parentheses. That means the exit will exit from the sub-shell rather than the shell you think it's running in.

But, unless you're absolutely desperate to keep it on one line, I'd just use:

if [[ ! -f "$DAEMON" ]] ; then
    echo "File $DAEMON not found"
    exit 0
fi

In such scenarios I using my errecho function, like

errecho() { echo "$@" >&2; return 1; }

the return 1 allows me chain the error condition, e.g. like

[[ -f file ]] || errecho "file doesnt exists" || exit 1

and it is useful for deeper functions too like

action() {

     [[ some cond ]] || errecho "errmsg" || return 1
}

do_something() {
    action "$1" "$3" || errecho "action failed with $3" || return 1
}

#main
do_something || errecho "total fail " || exit 1

use if statement:

if [ ! -f "$DAEMON" ]
then
  echo "File $DAEMON not found"
  exit 0
fi

You can use this if you want a single line solution and it works

[[ -f "filename" ]] || { echo "file doesnt exists" && exit ;}

echo "bye"

I didn't got the bye in console if the file not.

Use a loop and if statement. With the echo you can check until which point the script went. In the current case the script breaks if it encounters Daemon or C and so only echos A and B.

for i in A B Daemon C; do

if 
[ $i == Daemon ] || 
[ $i == C ]

then
    break
fi

echo "$i"

done