ginsh: 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/bin/ginsh - from package: ginac-tools

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

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