tiffinfo: 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/tiffinfo - from package: libtiff

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

On Debian possible default full paths are:

/usr/bin/tiffinfo - from package: libtiff-tools

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

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