chm_http: 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/chm_http - from package: chmlib

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

On Debian possible default full paths are:

/usr/bin/chm_http - from package: libchm-bin

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

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