js-yaml: 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 CentOS possible default full paths are:

/usr/bin/js-yaml - from package: nodejs-js-yaml

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

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