hmoment: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/hmoment - from package: emboss

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