pv.sh: 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/pv.sh - from package: ghostscript

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

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