pocommentclean: 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/pocommentclean - from package: translate-toolkit

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

On Debian possible default full paths are:

/usr/bin/pocommentclean - from package: translate-toolkit

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

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