oai_browser: 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 Debian possible default full paths are:

/usr/bin/oai_browser - from package: libhttp-oai-perl

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

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