shpdxf: 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/shpdxf - from package: shapelib

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

On Debian possible default full paths are:

/usr/bin/shpdxf - from package: shapelib

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

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