capiinit: 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:

/sbin/capiinit - from package: isdn4k-utils
/usr/sbin/capiinit - from package: isdn4k-utils

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

On Debian possible default full paths are:

/usr/sbin/capiinit - from package: capiutils

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

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