swig: 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/swig - from package: swig

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

On Debian possible default full paths are:

/usr/bin/swig - from package: swig

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

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