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Re: string types

From: Bruno Haible
Subject: Re: string types
Date: Sun, 29 Dec 2019 10:19:07 +0100
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Aga wrote:
>   - the returned value of the *printf family of functions dictates their
>     limits/range, as they return an int, this can be as INT_MAX mostly

Yes, we need new implementations of the *asprintf functions that are not
limited to returning strings of maximum length INT_MAX.

>   - as since there is a "risk"¹ that someone has to take at some point 
> (either the
>     programmer or the underlying library code (as strdup() does)), the 
> designed
>     interface should lower those risks

I agree with the goal. How to do it precisely, is an art however.

> In the case of an error, returns > 0 which is either:
> #define   EDSTPAR   -1                /* Error : bad dst parameters */
> #define   ESRCPAR   -2                /* Error : bad src parameters */
> #define   EMODPAR   -3                /* Error : bad mode parameter */
> #define   ETRUNC    -4                /* Error : not enough space to 
> copy/concatenate
>                                                          and truncation not 
> allowed */

I don't think an interface for string concatenation with that many error
cases will be successful. Programmers are lazy, therefore
  - some will not check the errors at all,
  - some will only check for the fourth one (because "I'm not passing invalid
    arguments, after all"),
  - among those few that implement all 4 checks, half will get it wrong
    (that's my experience with similarly complex functions like mbrtowc() or

For an interface to be successful, it needs to be simpler than that.


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