zegrapher: command not found

Have You tried accessing the binary with the full path?

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/zegrapher - from package: zegrapher

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