abc: 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 Debian possible default full paths are:

/usr/share/solr/bin/abc - from package: solr-common

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

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