img2txt: 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 CentOS possible default full paths are:

/usr/bin/img2txt - from package: caca-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/img2txt - from package: caca-utils

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

Error in other languages:
img2txt: bevel nie gevind nie
img2txt: comandă negăsită
img2txt: comando não encontrado
img2txt: commande introuvable
img2txt: command not found
img2txt: käsku ei ole
img2txt: không tìm thấy lệnh
img2txt: komanda nerasta
img2txt: Kommando nicht gefunden.
img2txt: kommandot finns inte
img2txt: komut yok
img2txt: nie znaleziono polecenia
img2txt: níor aimsíodh an t-ordú
img2txt: no se encontró la orden
img2txt: no s'ha trobat l'ordre
img2txt: opdracht niet gevonden
img2txt: parancs nem található
img2txt: perintah tidak ditemukan
img2txt: príkaz nenájdený
img2txt: příkaz nenalezen
img2txt: команда не найдена
img2txt: командата не е открита
img2txt: 命令找不到
img2txt: コマンドが見つかりません