ustr-import: 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/ustr-import - from package: ustr-devel

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

On Debian possible default full paths are:

/usr/bin/ustr-import - from package: libustr-dev

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

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