purple-url-handler: 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/purple-url-handler - from package: libpurple

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

On Debian possible default full paths are:

/usr/bin/purple-url-handler - from package: libpurple-bin

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