h2ph: command not found

Have You tried accessing the binary with the full path?

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/h2ph - from package: perl

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

On Debian possible default full paths are:

/usr/bin/h2ph - from package: perl

You may install the required package with command apt-get install {package}
Error in other languages:
h2ph: bevel nie gevind nie
h2ph: comandă negăsită
h2ph: comando não encontrado
h2ph: commande introuvable
h2ph: command not found
h2ph: käsku ei ole
h2ph: không tìm thấy lệnh
h2ph: komanda nerasta
h2ph: Kommando nicht gefunden.
h2ph: kommandot finns inte
h2ph: komut yok
h2ph: nie znaleziono polecenia
h2ph: níor aimsíodh an t-ordú
h2ph: no se encontró la orden
h2ph: no s'ha trobat l'ordre
h2ph: opdracht niet gevonden
h2ph: parancs nem található
h2ph: perintah tidak ditemukan
h2ph: príkaz nenájdený
h2ph: příkaz nenalezen
h2ph: команда не найдена
h2ph: командата не е открита
h2ph: 命令找不到
h2ph: コマンドが見つかりません