src/libopts/compat/snprintf.c

   1
   2 #ifndef HAVE_VPRINTF
   3 #include "choke-me: no vprintf and no snprintf"
   4 #endif
   5
   6 #if defined(HAVE_STDARG_H)
   7 #  include <stdarg.h>
   8 #  ifndef   VA_START
   9 #    define VA_START(a, f)  va_start(a, f)
  10 #    define VA_END(a)       va_end(a)
  11 #  endif /* VA_START */
  12 #  define SNV_USING_STDARG_H
  13
  14 #elif defined(HAVE_VARARGS_H)
  15 #  include <varargs.h>
  16 #  ifndef   VA_START
  17 #    define VA_START(a, f) va_start(a)
  18 #    define VA_END(a)    va_end(a)
  19 #  endif /* VA_START */
  20 #  undef  SNV_USING_STDARG_H
  21
  22 #else
  23 #  include "must-have-stdarg-or-varargs"
  24 #endif
  25
  26 static int
  27 snprintf(char *str, size_t n, char const *fmt, ...)
  28 {
  29     va_list ap;
  30     int rval;
  31
  32 #ifdef VSPRINTF_CHARSTAR
  33     char *rp;
  34     VA_START(ap, fmt);
  35     rp = vsprintf(str, fmt, ap);
  36     VA_END(ap);
  37     rval = strlen(rp);
  38
  39 #else
  40     VA_START(ap, fmt);
  41     rval = vsprintf(str, fmt, ap);
  42     VA_END(ap);
  43 #endif
  44
  45     if (rval > n) {
  46         fprintf(stderr, "snprintf buffer overrun %d > %d\n", rval, (int)n);
  47         abort();
  48     }
  49     return rval;
  50 }
  51
  52 static int
  53 vsnprintf( char *str, size_t n, char const *fmt, va_list ap )
  54 {
  55 #ifdef VSPRINTF_CHARSTAR
  56     return (strlen(vsprintf(str, fmt, ap)));
  57 #else
  58     return (vsprintf(str, fmt, ap));
  59 #endif
  60 }