flite: 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/flite - from package: flite

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

On Debian possible default full paths are:

/usr/bin/flite - from package: flite

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

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