glav: 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/glav - from package: mjpegtools-gtk

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