[Aiuto] Risolvere esercizi bash

[__casper__]

Esercizio 1:

if (( $# != 2 )); then
    echo "$0: Numero argomenti inesatto"
    echo "$0: Uso: $0 DIRECTORY ESTENSIONE"
    exit 1
fi

if ! [[ -d $1 ]]; then
    if ! [[ -e $1 ]]; then
        echo "$0: $1: Directory non esistente"
    else
        echo "$0: $1: Non e' una directory"
    fi
    exit 1
fi

directory=$1
ext=$2

for entry in $( ls $directory  ); do
    if echo $entry | grep -q \.$ext$; then
        echo $entry
    fi
done

Esercizio 3:

for user in $( who | awk '{ print $1 }'); do
    touch $user.txt
done