SO - 3 temat

2.

ls | grep .txt
for i in *.txt; do echo $i ; done

3.

#!/bin/bash
for i in *;
do
if [ -d $i ];
then
echo $i >>katalog.txt
fi
done

4.

n=1;
for i in *;
do
if [ -f $i ];
then
mv $i plik$n;
n=$[n+1];
fi
done