caret5: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/caret5 - from package: caret
/usr/lib/caret/bin/caret5 - from package: caret

You may install the required package with command apt-get install {package}

Error in other languages:
caret5: bevel nie gevind nie
caret5: comandă negăsită
caret5: comando não encontrado
caret5: commande introuvable
caret5: command not found
caret5: käsku ei ole
caret5: không tìm thấy lệnh
caret5: komanda nerasta
caret5: Kommando nicht gefunden.
caret5: kommandot finns inte
caret5: komut yok
caret5: nie znaleziono polecenia
caret5: níor aimsíodh an t-ordú
caret5: no se encontró la orden
caret5: no s'ha trobat l'ordre
caret5: opdracht niet gevonden
caret5: parancs nem található
caret5: perintah tidak ditemukan
caret5: príkaz nenájdený
caret5: příkaz nenalezen
caret5: команда не найдена
caret5: командата не е открита
caret5: 命令找不到
caret5: コマンドが見つかりません