common-functions: 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:

/var/spool/hylafax/bin/common-functions - from package: hylafax+-client

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

On Debian possible default full paths are:

/var/spool/hylafax/bin/common-functions - from package: hylafax-server

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

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