abcde: 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/abcde - from package: abcde

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

On Debian possible default full paths are:

/usr/bin/abcde - from package: abcde

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

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