csearch: 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 Debian possible default full paths are:

/usr/bin/csearch - from package: codesearch

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

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