sha1hmac: 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/sha1hmac - from package: hmaccalc

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

Error in other languages:
sha1hmac: bevel nie gevind nie
sha1hmac: comandă negăsită
sha1hmac: comando não encontrado
sha1hmac: commande introuvable
sha1hmac: command not found
sha1hmac: käsku ei ole
sha1hmac: không tìm thấy lệnh
sha1hmac: komanda nerasta
sha1hmac: Kommando nicht gefunden.
sha1hmac: kommandot finns inte
sha1hmac: komut yok
sha1hmac: nie znaleziono polecenia
sha1hmac: níor aimsíodh an t-ordú
sha1hmac: no se encontró la orden
sha1hmac: no s'ha trobat l'ordre
sha1hmac: opdracht niet gevonden
sha1hmac: parancs nem található
sha1hmac: perintah tidak ditemukan
sha1hmac: príkaz nenájdený
sha1hmac: příkaz nenalezen
sha1hmac: команда не найдена
sha1hmac: командата не е открита
sha1hmac: 命令找不到
sha1hmac: コマンドが見つかりません