shjs: 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/shjs - from package: nodejs-shelljs
/usr/lib/node_modules/shelljs/bin/shjs - from package: nodejs-shelljs

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

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