mc/lib/vfs
Amadeusz Sławiński 33c47b5734 Ticket #3025: race condition when creating temporary directory.
When there's no mc-tmpdir and a user tries to start two mc sessions
simultaneously, sometimes (in one out of ten attempts on my machine) one
mc session emits the following error message:

Cannot create temporary directory /tmp/mc-lars: File exists (17)
Temporary files will be created in /tmp
Press any key to continue...

Steps to reproduce:

# rm /tmp/mc-$(whoami) -rf
# uxterm -e mc & uxterm -e mc

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
2013-07-05 20:58:41 +04:00
..
direntry.c Remove vfs_path_to_str() function for avoid often memory allocations. 2013-06-03 14:21:01 +03:00
gc.c Code reorganization and fixes around the vfs_path_as_str() function 2013-06-28 09:21:16 +04:00
gc.h Following prototypes of functions was changed in VFS-module API: 2011-06-23 14:44:58 +03:00
HACKING VFS structure changes: 2011-03-21 11:48:26 +02:00
interface.c Ticket #3025: race condition when creating temporary directory. 2013-07-05 20:58:41 +04:00
Makefile.am Clarify usage of AM_CPPFLAGS. 2012-12-18 16:27:49 +04:00
netutil.c Clarify of sig_atomic_t usage (got from Mutt). 2012-11-09 10:05:13 +04:00
netutil.h Clarify of sig_atomic_t usage (got from Mutt). 2012-11-09 10:05:13 +04:00
parse_ls_vga.c Use "'" instead of "`" for messages and comments quoting. 2013-06-03 14:21:03 +03:00
path.c (vfs_get_encoding): optimization and enhancement: 2013-06-03 14:21:02 +03:00
path.h (vfs_path_as_string): clarify return value. 2013-06-28 09:21:16 +04:00
README VFS structure changes: 2011-03-21 11:48:26 +02:00
utilvfs.c Concretize the usage of autocompliting in different input fields. 2013-02-04 15:48:21 +03:00
utilvfs.h Changed input parameters of mc_mkstemp() and mc_tempdir() functions 2012-03-06 11:41:26 +03:00
vfs.c Remove vfs_path_to_str() function for avoid often memory allocations. 2013-06-03 14:21:01 +03:00
vfs.h Code reorganization and fixes around the vfs_path_as_str() function 2013-06-28 09:21:16 +04:00
xdirentry.h Indentation. 2012-12-20 16:22:23 +04:00

NOTE: Although vfs has been meant to be implemented as a separate
entity redistributable under the LGPL in its current implementation it
uses GPLed code from src/. So there are two possibilities if you want
to use vfs:

1. Distribute your copy of vfs under the GPL. Then you can freely
include the GPLed functions from the rest of the mc source code.

2. Distribute your copy of vfs under the LGPL. Then you cannot include
the functions outside the vfs subdirectory. You must then either
rewrite them or work around them in other ways.

========================================================================

Hi!

I'm midnight commander's vfs layer. Before you start hacking me,
please read this file. I'm integral part of midnight commander, but I
try to go out and live my life myself as a shared library, too. That
means that I should try to use as little functions from midnight as
possible (so I'm tiny, nice and people like me), that I should not
pollute name space by unnecessary symbols (so I do not crash fellow
programs) and that I should have a clean interface between myself and
midnight.

Because I'm rather close to midnight, try to:

* Keep the indentation as the rest of the code. Following could help
you with your friend emacs:

(defun mc-c-mode ()
	"C mode with adjusted defaults for use with the Midnight commander."
	(interactive)
	(c-mode)
	(c-set-style "K&R")
	(setq	c-indent-level 4
		c-continued-statement-offset 4
		c-brace-offset 0
		c-argdecl-indent 4
		c-label-offset -4
		c-brace-imaginary-offset 0
		c-continued-brace-offset 0
		c-tab-always-indent nil
		c-basic-offset 4
		tab-width 8
		comment-column 60))

(setq auto-mode-alist (cons '(".*/mc/.*\\.[ch]$" . mc-c-mode)
                       auto-mode-alist))

And because I'm trying to live life on my own as libvfs.so, try to:

* Make sure all exported symbols are defined in vfs.h and begin with
'vfs_'.

* Do not make any references from midnight into modules like tar. It
would probably pollute name space and midnight would depend on concrete
configuration of libvfs. mc_setctl() and mc_ctl() are your
friends. (And mine too :-).

							 Pavel Machek
							 pavel@ucw.cz

PS: If you'd like to use my features in whole operating system, you
might want to link me to rpc.nfsd. On
http://atrey.karlin.mff.cuni.cz/~pavel/podfuk/podfuk.html you'll find
how to do it.

PPS: I have a friend, shared library called avfs, which is LD_PRELOAD
capable. You can reach her at http://www.inf.bme.hu/~mszeredi/avfs.