wmifinfo: 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/wmifinfo - from package: wmifinfo

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

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