pdffonts: 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/pdffonts - from package: poppler-utils

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

On Debian possible default full paths are:

/usr/bin/pdffonts - from package: poppler-utils

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

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