bug#16889: erratic behavior of cp command i.e while copying files (using *) from one directory to another directory

[Anil Kumar]

Here is version info of cp command
=======
cp --version
cp (GNU coreutils) 8.20
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Torbjörn Granlund, David MacKenzie, and Jim Meyering.'




On Wed, Feb 26, 2014 at 6:06 PM, Anil Kumar <address@hidden> wrote:
> Hello
>
> I have observed, one erratic behavior of cp command i.e while copying
> files (using *) from one directory to another directory if
> we miss destination directory then cp command copies content of 1st
> file into 2nd file of same source directory instead of giving any
> error.
>
> Here is the scenario:
>
> #ls -l
> total 8
> drwxr-xr-x 2 root root 4096 Feb 26 17:34 ddir
> drwxr-xr-x 2 root root 4096 Feb 26 17:36 sdir
>
>
> # echo "hello" > sdir/hello.txt
> # echo "bye" > sdir/bye.txt
>
> # cat sdir/hello.txt
> hello
>
> # cat sdir/bye.txt
> bye
>
> # cp sdir/*.txt
>
> # cat sdir/hello.txt
> bye
>
> # cat sdir/bye.txt
> bye
>
> [Anil] Not sure, why "cp sdir/*.txt" command has copied data of
> bye.txt into hello.txt ? I think, its not desired behavior.
>  'cp' command should have produced error e.g destination is missing etc .
>
> One more example of similar behavior:
> # echo "hello" > sdir/hello.txt
> # echo "bye" > sdir/bye.txt
>
> # cat sdir/hello.txt
> hello
>
> # cat sdir/bye.txt
> bye
>
> # cp sdir/*
>
> # cat sdir/hello.txt
> bye
>
> # cat sdir/bye.txt
> bye
>
> [Anil]Here again "bye" has been copied into hello.txt which is not
> desired behavior.
>
> Here is strace output command "strace  cp sdir/*"
>
> stat("sdir/hello.txt", {st_mode=S_IFREG|0644, st_size=6, ...}) = 0
> stat("sdir/bye.txt", {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
> stat("sdir/hello.txt", {st_mode=S_IFREG|0644, st_size=6, ...}) = 0
> open("sdir/bye.txt", O_RDONLY)          = 3
> fstat(3, {st_mode=S_IFREG|0644, st_size=4, ...}) = 0
> open("sdir/hello.txt", O_WRONLY|O_TRUNC) = 4
> fstat(4, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> fadvise64(3, 0, 0, POSIX_FADV_SEQUENTIAL) = 0
> read(3, "bye\n", 65536)                 = 4
> write(4, "bye\n", 4)                    = 4
> read(3, "", 65536)                      = 0
> close(4)                                = 0
> close(3)                                = 0
> lseek(0, 0, SEEK_CUR)                   = -1 ESPIPE (Illegal seek)
> close(0)                                = 0
> close(1)                                = 0
> close(2)                                = 0
> exit_group(0)                           = ?