pst2ldif: 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/pst2ldif - from package: libpst

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

On Debian possible default full paths are:

/usr/bin/pst2ldif - from package: pst-utils

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

Error in other languages:
pst2ldif: bevel nie gevind nie
pst2ldif: comandă negăsită
pst2ldif: comando não encontrado
pst2ldif: commande introuvable
pst2ldif: command not found
pst2ldif: käsku ei ole
pst2ldif: không tìm thấy lệnh
pst2ldif: komanda nerasta
pst2ldif: Kommando nicht gefunden.
pst2ldif: kommandot finns inte
pst2ldif: komut yok
pst2ldif: nie znaleziono polecenia
pst2ldif: níor aimsíodh an t-ordú
pst2ldif: no se encontró la orden
pst2ldif: no s'ha trobat l'ordre
pst2ldif: opdracht niet gevonden
pst2ldif: parancs nem található
pst2ldif: perintah tidak ditemukan
pst2ldif: príkaz nenájdený
pst2ldif: příkaz nenalezen
pst2ldif: команда не найдена
pst2ldif: командата не е открита
pst2ldif: 命令找不到
pst2ldif: コマンドが見つかりません