langident: 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/langident - from package: liblingua-identify-perl

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

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