osd_cat: 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/osd_cat - from package: xosd

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

On Debian possible default full paths are:

/usr/bin/osd_cat - from package: xosd-bin

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

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