history.cgi: 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/lib/xymon/server/bin/history.cgi - from package: xymon

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

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