Re: new module: xprintf

[Bruno Haible]

Hi Jim,

> I've just added a new module:
> 
>     http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=78da34d40e6a2

Thanks; this module is necessary.

Two suggestions:

- Add a call to va_end() that matches the va_start() call. POSIX says:
  "Each invocation of the va_start() and va_copy() macros shall be matched
   by a corresponding invocation of the va_end() macro in the same function."

- I would make it clearer in the error message that the error is about
  formatted output. I don't feel that "write error" is good enough, given
  that the usual reasons for failing printf(), when !ferror(stream), are:
    EINVAL - invalid format string
    EILSEQ - cannot convert a wide character string
    ENOMEM - out of memory
  and these are not immediately related to writing on the stream.

How about this?


*** lib/xprintf.c.orig  2007-10-20 15:27:04.000000000 +0200
--- lib/xprintf.c       2007-10-20 15:20:34.000000000 +0200
***************
*** 38,44 ****
    va_start (args, format);
    int err = vprintf (format, args);
    if (err < 0 && ! ferror (stdout))
!     error (exit_failure, errno, gettext ("write error"));
  
    return err;
  }
--- 38,45 ----
    va_start (args, format);
    int err = vprintf (format, args);
    if (err < 0 && ! ferror (stdout))
!     error (exit_failure, errno, gettext ("cannot perform formatted output"));
!   va_end (args);
  
    return err;
  }
***************
*** 52,58 ****
    va_start (args, format);
    int err = vfprintf (stream, format, args);
    if (err < 0 && ! ferror (stream))
!     error (exit_failure, errno, gettext ("write error"));
  
    return err;
  }
--- 53,60 ----
    va_start (args, format);
    int err = vfprintf (stream, format, args);
    if (err < 0 && ! ferror (stream))
!     error (exit_failure, errno, gettext ("cannot perform formatted output"));
!   va_end (args);
  
    return err;
  }