abacas: 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
/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/abacas - from package: abacas

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