mirror of
https://github.com/reactos/reactos.git
synced 2024-12-29 10:35:28 +00:00
55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
|
#include <sys/types.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include "Strn.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Concatenate src on the end of dst. The resulting string will have at most
|
||
|
|
* n-1 characters, not counting the NUL terminator which is always appended
|
||
|
|
* unlike strncat. The other big difference is that strncpy uses n as the
|
||
|
|
* max number of characters _appended_, while this routine uses n to limit
|
||
|
|
* the overall length of dst.
|
||
|
|
*
|
||
|
|
* This routine also differs in that it returns a pointer to the end
|
||
|
|
* of the buffer, instead of strncat which returns a pointer to the start.
|
||
|
|
*/
|
||
|
|
char *
|
||
|
|
Strnpcat(char *const dst, const char *const src, size_t n)
|
||
|
|
{
|
||
|
|
register size_t i;
|
||
|
|
register char *d;
|
||
|
|
register const char *s;
|
||
|
|
register char c;
|
||
|
|
char *ret;
|
||
|
|
|
||
|
|
if (n != 0 && ((i = strlen(dst)) < (n - 1))) {
|
||
|
|
d = dst + i;
|
||
|
|
s = src;
|
||
|
|
/* If they specified a maximum of n characters, use n - 1 chars to
|
||
|
|
* hold the copy, and the last character in the array as a NUL.
|
||
|
|
* This is the difference between the regular strncpy routine.
|
||
|
|
* strncpy doesn't guarantee that your new string will have a
|
||
|
|
* NUL terminator, but this routine does.
|
||
|
|
*/
|
||
|
|
for (++i; i<n; i++) {
|
||
|
|
c = *s++;
|
||
|
|
if (c == '\0') {
|
||
|
|
ret = d; /* Return ptr to end byte. */
|
||
|
|
*d++ = c;
|
||
|
|
#if (STRNP_ZERO_PAD == 1)
|
||
|
|
/* Pad with zeros. */
|
||
|
|
for (; i<n; i++)
|
||
|
|
*d++ = 0;
|
||
|
|
#endif /* STRNP_ZERO_PAD */
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
*d++ = c;
|
||
|
|
}
|
||
|
|
/* If we get here, then we have a full string, with n - 1 characters,
|
||
|
|
* so now we NUL terminate it and go home.
|
||
|
|
*/
|
||
|
|
*d = 0;
|
||
|
|
return (d); /* Return ptr to end byte. */
|
||
|
|
}
|
||
|
|
return (dst);
|
||
|
|
} /* Strnpcat */
|