hocr-gtk: 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/hocr-gtk - from package: hocr-gtk

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

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