aleph: 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 CentOS possible default full paths are:

/usr/bin/aleph - from package: texlive

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/aleph - from package: texlive-binaries

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

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