xgettext: 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/xgettext - from package: gettext

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

On Debian possible default full paths are:

/usr/bin/xgettext - from package: gettext

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

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