ir.pl: 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/share/ledgersmb/bin/ir.pl - from package: ledgersmb
/usr/share/sql-ledger/bin/lynx/ir.pl - from package: sql-ledger
/usr/share/sql-ledger/bin/mozilla/ir.pl - from package: sql-ledger

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