randomlinks: 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/circos/tools/randomlinks/bin/randomlinks - from package: circos-tools

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

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