tax2thesaurus: 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/tax2thesaurus - from package: libbiblio-thesaurus-perl

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

Error in other languages:
tax2thesaurus: bevel nie gevind nie
tax2thesaurus: comandă negăsită
tax2thesaurus: comando não encontrado
tax2thesaurus: commande introuvable
tax2thesaurus: command not found
tax2thesaurus: käsku ei ole
tax2thesaurus: không tìm thấy lệnh
tax2thesaurus: komanda nerasta
tax2thesaurus: Kommando nicht gefunden.
tax2thesaurus: kommandot finns inte
tax2thesaurus: komut yok
tax2thesaurus: nie znaleziono polecenia
tax2thesaurus: níor aimsíodh an t-ordú
tax2thesaurus: no se encontró la orden
tax2thesaurus: no s'ha trobat l'ordre
tax2thesaurus: opdracht niet gevonden
tax2thesaurus: parancs nem található
tax2thesaurus: perintah tidak ditemukan
tax2thesaurus: príkaz nenájdený
tax2thesaurus: příkaz nenalezen
tax2thesaurus: команда не найдена
tax2thesaurus: командата не е открита
tax2thesaurus: 命令找不到
tax2thesaurus: コマンドが見つかりません