undelall: 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/undelall - from package: xbase-utils

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

On Debian possible default full paths are:

/usr/bin/undelall - from package: libxbase64-bin

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

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