x_edit: 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 CentOS possible default full paths are:

/usr/bin/x_edit - from package: GMT

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/gmt/bin/x_edit - from package: GMT

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