kmk_expr: 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/kmk_expr - from package: kBuild

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

On Debian possible default full paths are:

/usr/bin/kmk_expr - from package: kBuild

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

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