pdfpc: 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 Debian possible default full paths are:

/usr/bin/pdfpc - from package: pdf-presenter-console

You may install the required package with command apt-get install {package}

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