You do realize using strncmp means that a filename like .abc or ..whatever will also get hidden? There is no notion of a hidden file in Plan 9, nor is there an option to ls to show them. It's only necessary to hide . and .., not whatever the other system feels is a hidden file.

Also note that FTP servers using FAT don't use . to hide files - there's a bit in the attribute field. This will mean trouble for one with long file names, where the placement of periods is much more lenient.

664a665,666
>                    if(!strcmp(".", field[7]) || !strcmp("..", field[7]))
>                            return nil;
675a678,679
>                    if(!strcmp(".", field[8], 2) || !strcmp("..", field[8]))
>                            return nil;
686a691,692
>                    if(!strcmp(".", field[9]) || !strcmp("..", field[9]))
>                            return nil;
697a704,705
>                    if(!strcmp(".", field[3]) || !strcmp("..", field[3]))
>                            return nil;
712a721,722
>                    if(!strcmp(".", field[0]) || !strcmp("..", field[0]))
>                            return nil;


On Apr 28, 2008, at 4:48 AM, eekee57 wrote:

Hi all. I had a problem trying to use dircp with ftpfs the other day,
and made a little patch to ftpfs to fix it.

The Problem: Many operating systems expose the psuedo-directories "."
and ".." in their directory structure, and understandably many FTP
servers running on those operating systems pass the pseudo-directories
on to their clients. Plan 9 does does not expose those psuedo-
directories, so Plan 9's tar program does not treat them specially.
ftpfs does not hide the pseudo-directories, so Plan 9 tar (and thus
the dircp script too) will fail on encountering them, getting into a
loop until the sequence of directory/../directory/../directory/../
etc. just gets too long. Note that tar may fail to pack all files in
the tree before failing.

My Fix: I have added a little code to ftpfs to hide the "." and ".."
directories when the server operating system is detected as UNIX,
Windows-NT, or Plan 9. I included the Plan 9 case because these 3
operating systems are lumped together in the code, and the heuristics
to tell them apart by detail may be fooled by some server which
happens to list files in a similar manner.

My code consists of 5 near-identical if statements in the function
that parses each line returned from an ftp LIST or NLST command:

664a665,666
                        if(!strncmp(".", field[7], 2) || !strncmp("..", 
field[7], 3))
                                return nil;
675a678,679
                        if(!strncmp(".", field[8], 2) || !strncmp("..", 
field[8], 3))
                                return nil;
686a691,692
                        if(!strncmp(".", field[9], 2) || !strncmp("..", 
field[9], 3))
                                return nil;
697a704,705
                        if(!strncmp(".", field[3], 2) || !strncmp("..", 
field[3], 3))
                                return nil;
712a721,722
                        if(!strncmp(".", field[0], 2) || !strncmp("..", 
field[0], 3))
                                return nil;

return nil results in ftpfs ignoring that line of the listing
entirely. strncmp() may not be the best function as it is supposed to
compare lexicographically. I'm not sure whether a "lexicographic"
comparison is appropriate, but I think Plan 9 strncmp is currently a
simple byte-by-byte comparison.

Patched /sys/src/cmd/ip/ftpfs/proto.c file:
http://eekee.org.uk/plan9/ftpfs..patch/proto.c

Also FYC are an ed script and a context diff:
http://eekee.org.uk/plan9/ftpfs..patch/diff.ed
http://eekee.org.uk/plan9/ftpfs..patch/diff.context



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