links: 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/links - from package: elinks
/usr/bin/links - from package: links

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

On Debian possible default full paths are:

/usr/bin/links - from package: links

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

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