antlr-config: 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/antlr-config - from package: antlr

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

On Debian possible default full paths are:

/usr/bin/antlr-config - from package: libantlr-dev

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

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