check-regexp: 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/check-regexp - from package: source-highlight

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

On Debian possible default full paths are:

/usr/bin/check-regexp - from package: source-highlight

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

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