svnlook: 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/svnlook - from package: subversion

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

On Debian possible default full paths are:

/usr/bin/svnlook - from package: subversion

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

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