sshpass: 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/sshpass - from package: sshpass

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

On Debian possible default full paths are:

/usr/bin/sshpass - from package: sshpass

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

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