lchfn: 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/lchfn - from package: libuser

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

On Debian possible default full paths are:

/usr/bin/lchfn - from package: libuser

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

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