Fsort.nawk: 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/share/ferret-vis/bin/Fsort.nawk - from package: ferret-vis

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

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