fitsverify: 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/fitsverify - from package: fitsverify

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

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