gsmc: 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/gsmc - from package: gsmc

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

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