tinyirc: 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/tinyirc - from package: tinyirc

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