You need to understand how unix modes and permissions, used on POSIX operating systems such as GNU/Linux and OSX work, otherwise your life is going to be full of awkward problems like this. There are already lots and lots of introductions online, I will not bother regurgitating them.
However, I'll give an example of applying the concepts in this case. First, you need to know some id numbers for your current user:
Will give you your
gid, and a list of groups whose permissions you can use.
./configure is a file. To get the modes and permissions set on it:
It's in the first line labelled "Access:" (there are two), and will be something like
0755/drwxr-xr-x. All of those links from above explain how to decipher that. See also
You need to change the ownership on the whole directory tree, since you are going to be building software in it. For that you can use the
-R (recursive) switch to
chown (see also
man chown), but you need privileges to do so, via
sudo. Presuming you are in the same directory as the
configure file, and you are user
sudo chown -R pi.pi .
You could of course just do
sudo ./configure and proceed that way, but this way you are playing safe. On the other hand, if you are intending to do a system wide install, you will need to do so at some point (
sudo make install).
Note that this is not necessarily an ownership problem, which will be obvious when you examine the files in question; it can also be purely mode related. To execute a file, it needs to be set as executable (adds 1 to the mode, e.g., 7 is read/write/execute, 6 is read/write, 5 is read/execute, 4 is just read). It would be a bit bizarre in this case, but certainly not impossible depending on how the source archive was unpacked and the USB drive mounted.