1)

#!/bin/sh

for soubor in *.jpeg
do
    mv "$soubor" "`echo "$soubor" | sed s/\.jpeg/\.jpg/`"
done

(Petr G.)
rename .jpeg .jpg ./*.jpeg

---

#!/bin/sh

for file in *.jpeg;
do
newname=$(echo $file | sed 's/\(.*\)\.jpeg$/\1.jpg/')
if [ -f "$newname" ];
then
    echo "Nemuzu prejmenovat"
else
    mv $file $newname
    fi
done

---

#!/bin/sh

for x in *.jpeg
do
  mv  "$x" "${x%.jpeg}.jpg";
done

2)

#!/bin/sh
ed "$1" <<KONEC
    $2s/^.*$/haha/
    w
KONEC

3)

(verzia - vlozenie)

#!/bin/sh

find $1 -type d -exec mkdir -p "$2/{}" \;

---

(verzia - sync)

#!/bin/sh

find $1 -type d | sed "s/$1\(.*\)/\1/" | xargs -I{} mkdir -p $2{}

---

#!/bin/sh

find "$1" -type d -printf "$2/%P\0" | xargs -0 mkdir -p

---

#!/bin/sh

find ${1} -type d | while read d
do
d=$(echo "$d" | sed "s/$1\(.*\)/$2\1/");
mkdir "$d"
done

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vzorove riesenia: Tereza K., Simon S., Viktor V., Antonin K., Ondrej V.

---

caste chyby:
'xxx$1xxx' vs "xxx$1xxx"
x = 'xxx' (mezery!)
$x='xxx' ($ sign)

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tip: `` alebo ${} pouzite na vyhodnotenie vyrazu
parameter expansion - vie urychlit veci, see http://wiki.bash-hackers.org/syntax/pe

---

Xtra-men:

Viktor V. - pouziti shift (posune argumenty v shell scriptu)
Viktor V. - pouziti | sh (echo $soubor | sed 's/\(.*\)\.jpeg/cp -p & \1.jpg' | sh

Ondra V., Michal H. - parameter expansion