perl_count: 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/perl_count - from package: sloccount

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

On Debian possible default full paths are:

/usr/bin/perl_count - from package: sloccount

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

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