jmacs: 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/jmacs - from package: joe

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

On Debian possible default full paths are:

/usr/bin/jmacs - from package: joe-jupp
/usr/bin/jmacs - from package: joe

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

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