Filename Too Long

[Martin v. Loewis]

rudi_sass at yahoo.com (Peter D) writes:

> I'm using windows and trying to call os.path.getmtime() after using
> os.path.walk... However, I'm choking with "[Errno 38] Filename too
> long" on paths with len > ~260
> 
> Is there any way around this error?

Since you are asking for a work-around: cd into one of the more nested
directories when the path gets longer (os.chdir), and use relative
paths from then on.

If you want to study how to solve the problem: the relevant code
snippet is in Modules/posixmodule.c

	/* the library call can blow up if the file name is too long! */
	if (pathlen > MAX_PATH) {
		PyMem_Free(pathfree);
		errno = ENAMETOOLONG;
		return posix_error();
	}

There might be different ways to approach this:

- challenge the correctness of the comment:
   - try to establish why the author of that code thought that the C
     library could blow up
   - analyse whether these arguments are still true with the current
     compiler version
  -or-
   - prove the argument wrong by analysing the source code of the C
     library
- then remove the constraint
-or-
- use different API to achieve the same effect without suffering from
  the constraint.

I'm serious about these suggestions: users would appreciate if this
gets fixed somehow - apparently, the system allows longer file names,
and apparently, the system itself can deal with that quite well. This
can be only true if the system either doesn't use its C library, or if
the C library does not have this restriction.

HTH,
Martin