shrinkfile: 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/lib/news/bin/shrinkfile - from package: inn2
/usr/lib/news/bin/shrinkfile - from package: inn

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

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