netsed: 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/netsed - from package: netsed

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

On Debian possible default full paths are:

/usr/bin/netsed - from package: netsed

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

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