OpenEuphoria

Euphoria Ticket #899: move_file can sometimes report success on failure

• Reported by SDPringle Jun 18, 2014
• 7 comments

include std/filesys.e 
include std/search.e 
include std/io.e as io 
include std/os.e as os 
 
-- include trailing slashes! 
constant source_dir = "/home/shawn/downloads/"  
constant dest_dir = "/media/FlashDrive/" 
 
sequence s = dir(source_dir & "*.dat") 
for i = 1 to length(s) do 
    sequence d_ent = s[i] 
    sequence d_name = d_ent[D_NAME] 
    if match("20 de", d_name) = 1 then 
        printf(io:STDOUT, "Found %s in downloads\n", {d_name})   
        if not move_file(source_dir & d_name, dest_dir & d_name) then 
            puts(io:STDERR, "Could not move " & d_name & " to flash drive.\n") 
        else 
            os:sleep(1) 
            printf(io:STDERR, "move_file reports the file %s has been successfully moved ", {d_name}) 
            if file_exists(dest_dir & d_name) then 
                puts(io:STDERR, "and so it has.\n") 
            else 
                puts(io:STDERR, "but it hasn't.\n") 
            end if 
        end if 
    end if 
end for 

Found 20 de Junio - Día de la Bandera Argentina.dat in downloads 
move_file reports the file 20 de Junio - Día de la Bandera Argentina.dat has been successfully moved and so it has. 

Found 20 de Junio - Día de la Bandera Argentina.dat in downloads 
move_file reports the file 20 de Junio - Día de la Bandera Argentina.dat has been successfully moved but it hasn't. 

Details

1. Comment by SDPringle Jun 18, 2014

Anytime there is another filesystem involved this routine inverts the success code which is okay when the success code is from UNIX C routines but not okay when calling other std/filesys.e routines. I am preparing a fix for this.

2. Comment by mattlewis Jun 18, 2014

That's very odd. I would guess that the problem is actually inside of copy_file(), and really in open(). Can you open a file for writing with that name on a VFAT disk?

I was able to open a file for writing with that name on VFAT.

3. Comment by SDPringle Jun 18, 2014

See: hg:euphoria/rev/a0120f6dc562

changeset: 6235:a0120f6dc562 tag: tip parent: 6218:d564cc9bc164 user: Shawn Pringle <shawn.pringle@gmail.com> date: Wed Jun 18 09:18:42 2014 -0300 files: include/std/filesys.e description:

• fixed move_file to return correct success code in the case of UNIX between distinct filesystems
• limit the scope of ret
• fixes ticket 899

4. Comment by SDPringle Jun 18, 2014

See: hg:euphoria/rev/faffe693f1dc

changeset: 6236:faffe693f1dc tag: tip user: Shawn Pringle <shawn.pringle@gmail.com> date: Wed Jun 18 09:32:33 2014 -0300 files: include/std/filesys.e description:

• fixes ticket 899

5. Comment by SDPringle Jun 18, 2014

@mattlewis The failure to move the file itself seems to be some kind of bug specific for my version of Linux. I cannot create 'Ah?.txt' with the touch command.

6. Comment by jimcbrown Jun 18, 2014

You can probbaly fix the original issue by playing with the codepage option to vfat: http://www.linuxquestions.org/questions/slackware-14/how-to-set-default-mount-codepage-for-vfat-partition-as-utf8-740681/

See also https://www.kernel.org/doc/Documentation/filesystems/vfat.txt

For others to reproduce the bug, maybe try to use the colon character : in the filename - that's illegal on vfat. Of course, newer kernels might have an option to emulate the colon character on vfat by encoding it differently or something....

7. Comment by SDPringle Jun 18, 2014

You can reproduce the bug much more easily if you are talking about that of this ticket.

bash-4.2# dd if=/dev/zero of=/tmp/tmpfs.fs bs=1k count=1000 
1000+0 records in 
1000+0 records out 
1024000 bytes (1.0 MB) copied, 0.0101574 s, 101 MB/s 
bash-4.2# mkfs -t minix /tmp/tmpfs.fs 
352 inodes 
1000 blocks 
Firstdatazone=15 (15) 
Zonesize=1024 
Maxsize=268966912 
 
bash-4.2# mkdir /media/FlashDrive;  
bash-4.2# mount /tmp/tmpfs.fs /media/FlashDrive -t minix -o loop,rw 
bash-4.2# su shawn 
bash-4.2$ cd 
bash-4.2$ touch ~/downloads/'20 de Junio.dat' 
bash-4.2$ cp ~/downloads/'20 de Junio.dat' /media/FlashDrive 
cp: cannot create regular file '/mnt/tmp/ex.err': Permission denied 
bash-4.2$ eui move.ex 
Found 20 de Junio.dat in downloads 
move_file reports the file 20 de Junio.dat has been successfully moved but it hasn't. 
 

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