Questions related to enhancing "tar"
Thu Jun 28 07:16:00 GMT 2001
>>>>> "John" == John David Galt <email@example.com> writes:
John> First off, correct me if I'm wrong, but I assume that
John> Cygwin's version of G++ uses the same underlying INT 21 BIOS
John> calls for file access as Windows does.
No. All Win32 programs, including the Cygwin programs, use the file
access routines of the Win32 API. They don't use DOS anymore, which
used to be the INT 21h interface you refer to.
John> The BIOS turns on the Archive attribute whenever a file is
Actually, DOS is the one that used to perform this function.
John> a) How do I read and write the Archive attribute bit from a
John> program compiled in G++ under Cygwin? Is it accessible
John> using ioctl(), and what are the parameters? (man pages that
John> specific don't appear to exist for Cygwin.)
Best place to look is in the source to the Cygwin DLL; refer to the
following "mirrors" list:
Grab the file cygwin-1.3.2-1-src.tar.gz, located in the latest/cygwin
directory. Check if the Win32 file attributes function (sorry, I
don't recall the name of the function of the top of my head) is being
John> b) Does Cygwin have its own separate version of "tar"? If
John> not, would they be willing to host one, or a link to mine?
Well, you could modify the Cygwin tar, I guess. However, I think an
easier thing to do is to write a shell script that calls tar to backup
your files, and then for each file, calls the 'attrib' program to
reset the archive bit. Implementation of such a script is pretty
straightforward, and thus, is left as an exercise to the reader... :-)
 Well, not directly, in the case of Win9x and WinME. For NT and
W2K, they don't use DOS at all.
Dario Alcocer -- Sr. Software Developer, Helix Digital Inc.
firstname.lastname@example.org -- http://www.helixdigital.com
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Bug reporting: http://cygwin.com/bugs.html
More information about the Cygwin