tab2space: 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/tab2space - from package: tidy

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

Error in other languages:
tab2space: bevel nie gevind nie
tab2space: comandă negăsită
tab2space: comando não encontrado
tab2space: commande introuvable
tab2space: command not found
tab2space: käsku ei ole
tab2space: không tìm thấy lệnh
tab2space: komanda nerasta
tab2space: Kommando nicht gefunden.
tab2space: kommandot finns inte
tab2space: komut yok
tab2space: nie znaleziono polecenia
tab2space: níor aimsíodh an t-ordú
tab2space: no se encontró la orden
tab2space: no s'ha trobat l'ordre
tab2space: opdracht niet gevonden
tab2space: parancs nem található
tab2space: perintah tidak ditemukan
tab2space: príkaz nenájdený
tab2space: příkaz nenalezen
tab2space: команда не найдена
tab2space: командата не е открита
tab2space: 命令找不到
tab2space: コマンドが見つかりません