txt2regex: 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/txt2regex - from package: txt2regex

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

On Debian possible default full paths are:

/usr/bin/txt2regex - from package: txt2regex

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

Error in other languages:
txt2regex: bevel nie gevind nie
txt2regex: comandă negăsită
txt2regex: comando não encontrado
txt2regex: commande introuvable
txt2regex: command not found
txt2regex: käsku ei ole
txt2regex: không tìm thấy lệnh
txt2regex: komanda nerasta
txt2regex: Kommando nicht gefunden.
txt2regex: kommandot finns inte
txt2regex: komut yok
txt2regex: nie znaleziono polecenia
txt2regex: níor aimsíodh an t-ordú
txt2regex: no se encontró la orden
txt2regex: no s'ha trobat l'ordre
txt2regex: opdracht niet gevonden
txt2regex: parancs nem található
txt2regex: perintah tidak ditemukan
txt2regex: príkaz nenájdený
txt2regex: příkaz nenalezen
txt2regex: команда не найдена
txt2regex: командата не е открита
txt2regex: 命令找不到
txt2regex: コマンドが見つかりません