xlsfonts: 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/xlsfonts - from package: xorg-x11-utils

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

On Debian possible default full paths are:

/usr/bin/xlsfonts - from package: x11-utils

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

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