Re: Difference between sprintf, snprintf and spprintf

Idea was that most people are not aware of spprintf and do not know the difference. So Markus and me thought about adding such a note. marcus At 23:44 22.06.2002, Sterling Hughes wrote:

Why? If you're commiting code you should know how to use these basic functions... besides, sprintf is not really all that bad...

I know but often people miscalculate buffer sizes....

-Sterling Proposal comment for spprintf/snprintf header. When nobody objects i commit this to spprintf.h and make a notice in snprintf.h. /* Comparing: sprintf, snprintf, spprintf sprintf offers the ability to make a lot of falures since it does not know

         the size of the buffer it uses. Therefore usage of sprintf often
         results in possible entries for buffer overrun attacks.
         SO PLEASE DO NOT USE IT!

snprintf knows the buffers size and will not write behind it. but you will

         have to use either a static buffer or allocate one dynamic buffer
         before beeing able to call the function. In other words you must
         be sure that you really know the maximum size of the buffer
         required.
         A bad thing is if you hav a big maximum and in most cases you only
         need a small buffer.

spprintf Is the dynamical version of snprintf it allocates the buffer in size

         as neede and allows a maximum setting as snprintf (turn this
         feature
         of by setting max_len to 0). spprintf is a little bit slower than
         snprintf and offers possible memory leakes if you miss freeing the
         buffer allocated by the function. Therfore this function should be
         used where either no maximum is known or the maximum is much bigger
         then normal size required.

Example: char *buffer; #define MAX 1024 spprintf(&buffer, MAX, "text"); if (!buffer)

    return OUT_OF_MEMORY

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