sesearch: 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/sesearch - from package: setools-console

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

On Debian possible default full paths are:

/usr/bin/sesearch - from package: setools

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

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