audacity: 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/audacity - from package: audacity

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

On Debian possible default full paths are:

/usr/bin/audacity - from package: audacity

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

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