openconnect: 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/sbin/openconnect - from package: openconnect

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

On Debian possible default full paths are:

/usr/sbin/openconnect - from package: openconnect

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

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