c-icap-mods-sguardDB: 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 Debian possible default full paths are:

/usr/bin/c-icap-mods-sguardDB - from package: libc-icap-mod-urlcheck

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