texmacs: 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

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/texmacs - from package: TeXmacs

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