ps2frag: 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/ps2frag - from package: texlive

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

On Debian possible default full paths are:

/usr/bin/ps2frag - from package: texlive-font-utils

You may install the required package with command apt-get install {package}
Error in other languages:
ps2frag: bevel nie gevind nie
ps2frag: comandă negăsită
ps2frag: comando não encontrado
ps2frag: commande introuvable
ps2frag: command not found
ps2frag: käsku ei ole
ps2frag: không tìm thấy lệnh
ps2frag: komanda nerasta
ps2frag: Kommando nicht gefunden.
ps2frag: kommandot finns inte
ps2frag: komut yok
ps2frag: nie znaleziono polecenia
ps2frag: níor aimsíodh an t-ordú
ps2frag: no se encontró la orden
ps2frag: no s'ha trobat l'ordre
ps2frag: opdracht niet gevonden
ps2frag: parancs nem található
ps2frag: perintah tidak ditemukan
ps2frag: príkaz nenájdený
ps2frag: příkaz nenalezen
ps2frag: команда не найдена
ps2frag: командата не е открита
ps2frag: 命令找不到
ps2frag: コマンドが見つかりません