source: trunk/libs/newlib/src/newlib/libc/string/strxfrm.c @ 444

/*
FUNCTION
        <<strxfrm>>---transform string

INDEX
        strxfrm

SYNOPSIS
        #include <string.h>
        size_t strxfrm(char *restrict <[s1]>, const char *restrict <[s2]>,
                       size_t <[n]>);

DESCRIPTION
        This function transforms the string pointed to by <[s2]> and
        places the resulting string into the array pointed to by
        <[s1]>. The transformation is such that if the <<strcmp>>
        function is applied to the two transformed strings, it returns
        a value greater than, equal to, or less than zero,
        correspoinding to the result of a <<strcoll>> function applied
        to the same two original strings.

        No more than <[n]> characters are placed into the resulting
        array pointed to by <[s1]>, including the terminating null
        character. If <[n]> is zero, <[s1]> may be a null pointer. If
        copying takes place between objects that overlap, the behavior
        is undefined.

        (NOT Cygwin:) The current implementation of <<strxfrm>> simply copies
        the input and does not support any language-specific transformations.

RETURNS
        The <<strxfrm>> function returns the length of the transformed string
        (not including the terminating null character). If the value returned
        is <[n]> or more, the contents of the array pointed to by
        <[s1]> are indeterminate.

PORTABILITY
<<strxfrm>> is ANSI C.

<<strxfrm>> requires no supporting OS subroutines.

QUICKREF
        strxfrm ansi pure
*/

#include <string.h>

size_t
strxfrm (char *__restrict s1,
        const char *__restrict s2,
        size_t n)
{
  size_t res;
  res = 0;
  while (n-- > 0)
    {
      if ((*s1++ = *s2++) != '\0')
        ++res;
      else
        return res;
    }
  while (*s2)
    {
      ++s2;
      ++res;
    }

  return res;
}