lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]


    I am curious, can you tell me of an example of where a NULL
character is interpreted by fgets() as an ending character? I
understand that reading in NULL (or '\0' in this case) directly to the
input buffer would result in most cases of having the new buffer
appear to end for any upcoming manipulations (i.e. any function
reading the resulting string would assume that the string ends at the
first '\0' character it encounters), however I don't believe fgets
cares about the NULL character any more than any other character
except for '\n', though I haven't looked at the source in a while. In
any case, in what sort of file would a NULL character appear that
could not be interpreted as EOF and yet still have data following it?

On Sun, Apr 13, 2008 at 8:09 PM, gary ng <> wrote:
>  --- Shmuel Zeigerman <> wrote:
>  > Here is an fgets specification from The Open Group:
>  >
>  > > The fgets() function shall read bytes from stream
>  > into the array
>  > > pointed to by s, until n-1 bytes are read, or a
>  > <newline> is read
>  > > and transferred to s, or an end-of-file condition
>  > is encountered.
>  > > The string is then terminated with a null byte.
>  >
>  >  From this specification, it is quite obvious that
>  > only <newline> is
>  > special in the input stream.
>  >
>  I have a very different reading. In fact, I think null
>  is a special case as C strings are null terminated.
>  Thus it implicitly means that fgets() would stop at
>  null OR '\n'. Especially the last line where it said a
>  final NULL would be appended.
>  Think if it doesn't stop at NULL of the input, then
>  anything beyond that is still invisible as caller of
>  this function expects the string to be a C string(i.e.
>  null terminated). So what is the point to read beyond
>  that ? If fact, without reading beyond that, a loop
>  can still read all the contents(sans NULL and \n) but
>  that still matches the 'lines of string' expectation
>  in C.
>  __________________________________________________
>  Do You Yahoo!?
>  Tired of spam?  Yahoo! Mail has the best spam protection around