datamash: 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/datamash - from package: datamash

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

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