ikiwiki-update-wikilist: command not found

Have You tried accessing the binary with the full path?

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/ikiwiki-update-wikilist - from package: ikiwiki

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

On Debian possible default full paths are:

/usr/bin/ikiwiki-update-wikilist - from package: ikiwiki

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