/* FUNCTION <<stpcpy>>---copy string returning a pointer to its end INDEX stpcpy SYNOPSIS #include <string.h> char *stpcpy(char *restrict <[dst]>, const char *restrict <[src]>); DESCRIPTION <<stpcpy>> copies the string pointed to by <[src]> (including the terminating null character) to the array pointed to by <[dst]>. RETURNS This function returns a pointer to the end of the destination string, thus pointing to the trailing '\0'. PORTABILITY <<stpcpy>> is a GNU extension, candidate for inclusion into POSIX/SUSv4. <<stpcpy>> requires no supporting OS subroutines. QUICKREF stpcpy gnu */ #include <string.h> #include <limits.h> /*SUPPRESS 560*/ /*SUPPRESS 530*/ /* Nonzero if either X or Y is not aligned on a "long" boundary. */ #define UNALIGNED(X, Y) \ (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) #if LONG_MAX == 2147483647L #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) #else #if LONG_MAX == 9223372036854775807L /* Nonzero if X (a long int) contains a NULL byte. */ #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) #else #error long int is not a 32bit or 64bit type. #endif #endif #ifndef DETECTNULL #error long int is not a 32bit or 64bit byte #endif char* _DEFUN (stpcpy, (dst, src), char *__restrict dst _AND _CONST char *__restrict src) { #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) long *aligned_dst; _CONST long *aligned_src; /* If SRC or DEST is unaligned, then copy bytes. */ if (!UNALIGNED (src, dst)) { aligned_dst = (long*)dst; aligned_src = (long*)src; /* SRC and DEST are both "long int" aligned, try to do "long int" sized copies. */ while (!DETECTNULL(*aligned_src)) { *aligned_dst++ = *aligned_src++; } dst = (char*)aligned_dst; src = (char*)aligned_src; } #endif /* not PREFER_SIZE_OVER_SPEED */ while ((*dst++ = *src++)) ; return --dst; }