strainextract: 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/bin/strainextract - from package: esys-particle

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

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