ossim-swapbytes: 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/bin/ossim-swapbytes - from package: ossim-core

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