markerpos.txt: 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/share/doc/r-cran-qtl/examples/bin/test/markerpos.txt - from package: r-cran-qtl

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

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