newlib-cygwin/newlib/libc/string/strxfrm.c

76 lines
1.6 KiB
C

/*
FUNCTION
<<strxfrm>>---transform string
INDEX
strxfrm
ANSI_SYNOPSIS
#include <string.h>
size_t strxfrm(char *<[s1]>, const char *<[s2]>, size_t <[n]>);
TRAD_SYNOPSIS
#include <string.h>
size_t strxfrm(<[s1]>, <[s2]>, <[n]>);
char *<[s1]>;
char *<[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.
With a C locale, this function just copies.
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
_DEFUN (strxfrm, (s1, s2, n),
char *s1 _AND
_CONST char *s2 _AND
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;
}