aclocal: command not found

Have You tried accessing the binary with the full path?

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/aclocal - from package: automake

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