Question: Is there a way to determine if the process *may* execute a file without having to actually execute it (e.g. by calling `execv(filepath, args)` only to fail and discover that `errno == EACCES`)?

I could `stat` the file and observe `st_mode`, but then I still don’t know how that pertains to the process.

Ideally, I’m looking for a function along the lines of

```
get_me_permissions(filepath, &status); // me: the process calling this function
// when decoded, status tells if the process can read, write, and/or execute 
// the file given by filepath.

```

Thanks in advance.

Answer: 
<http://linux.die.net/man/2/access>

Note the slight tricksiness around suid - if the process has effective superuser privilege it isn't taken into account, since the general idea of the function is to check whether the original invoking user *should* have access to the file, not to check whether this process *could* access the file.
Assuming your end goal is to eventually execute the program, you don't. This test would be useless because the result is potentially wrong even before the function to make the check returns! You must be prepared to handle failure of `execve` due to permission errors.

As pointed out by Steve Jessop, checking whether a given file is executable *can* be useful in some situations, such as a file listing (`ls -l`) or visual file manager. One could certainly think of more esoteric uses such a using the permission bits of a file for inter-process communication (interesting as a method which would not require any resource allocation), but I suspect `stat` ("What are the permission bits set to?") rather than `access` ("Does the calling process have X permission?") is more likely to be the interesting question...