psjoin: command not found

Have You tried accessing the binary with the full path?

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/bin/psjoin - from package: psutils

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