g.access: 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/lib64/grass-6.4.4/bin/g.access - from package: grass

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

On Debian possible default full paths are:

/usr/lib/grass64/bin/g.access - from package: grass-core

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

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