Re: [PATCH] Use strdup in dd to avoid changing argv elements

[Andreas Schwab]

Jim Meyering <address@hidden> writes:

> Eric Blake <address@hidden> wrote:
>
>> According to Jim Meyering on 1/28/2008 6:28 AM:
>> |
>> | Thanks for the suggestion, but that introduces a new way for
>> | dd to fail: strdup returning NULL would often lead to a segfault.
>> | Even if it were to use xstrdup, to avoid that, I don't think it's
>> | justifiable solely in order to preserve ps' view of the dd command line.
>>
>> However, it IS justifiable by the fact that POSIX requires applications to
>> treat argv[] as constant (ie. modifying argv in-place is not
>> standards-compliant).  True, most systems let you get away with
>> modifications (in particular, think about getopt_long's behavior), but it
>> would matter if we ever port coreutils to a system that follows the POSIX
>> permission to insist on no modifications to the original argv and contents.
>>
>> http://www.opengroup.org/onlinepubs/009695399/functions/execl.html
>> "The statement about argv[] and envp[] being constants is included to make
>> explicit to future writers of language bindings that these objects are
>> completely constant. Due to a limitation of the ISO C standard, it is not
>> possible to state that idea in standard C."
>
> Good point.  Thanks.

Except that the point has nothing to do with how the arguments are
passed to the executed process.

Andreas.

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Andreas Schwab, SuSE Labs, address@hidden
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