xscreensaver-text: command not found

Have You tried accessing the binary with the full path?

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/xscreensaver-text - from package: xscreensaver-base

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

On Debian possible default full paths are:

/usr/bin/xscreensaver-text - from package: xscreensaver-data

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