lz4c: 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/lz4c - from package: lz4

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

On Debian possible default full paths are:

/usr/bin/lz4c - from package: liblz4-tool

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

Error in other languages:
lz4c: bevel nie gevind nie
lz4c: comandă negăsită
lz4c: comando não encontrado
lz4c: commande introuvable
lz4c: command not found
lz4c: käsku ei ole
lz4c: không tìm thấy lệnh
lz4c: komanda nerasta
lz4c: Kommando nicht gefunden.
lz4c: kommandot finns inte
lz4c: komut yok
lz4c: nie znaleziono polecenia
lz4c: níor aimsíodh an t-ordú
lz4c: no se encontró la orden
lz4c: no s'ha trobat l'ordre
lz4c: opdracht niet gevonden
lz4c: parancs nem található
lz4c: perintah tidak ditemukan
lz4c: príkaz nenájdený
lz4c: příkaz nenalezen
lz4c: команда не найдена
lz4c: командата не е открита
lz4c: 命令找不到
lz4c: コマンドが見つかりません