htsearch: 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/htsearch - from package: htdig

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

On Debian possible default full paths are:

/usr/lib/axiom-20140801/bin/htsearch - from package: axiom-hypertex

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

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