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STRCPY(3)		 BSD Library Functions Manual		     STRCPY(3)

NAME
     stpcpy, stpncpy, strcpy, strncpy -- copy strings

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <string.h>

     char *
     stpcpy(char * restrict dst, const char * restrict src);

     char *
     stpncpy(char * restrict dst, const	char * restrict	src, size_t len);

     char *
     strcpy(char * restrict dst, const char * restrict src);

     char *
     strncpy(char * restrict dst, const	char * restrict	src, size_t len);

DESCRIPTION
     The stpcpy() and strcpy() functions copy the string src to	dst (including
     the terminating `\0' character.)

     The stpncpy() and strncpy() functions copy	at most	len characters from
     src into dst.  If src is less than	len characters long, the remainder of
     dst is filled with	`\0' characters.  Otherwise, dst is not	terminated.

RETURN VALUES
     The strcpy() and strncpy()	functions return dst.  The stpcpy() and
     stpncpy() functions return	a pointer to the terminating `\0' character of
     dst.  If stpncpy()	does not terminate dst with a NUL character, it	in-
     stead returns a pointer to	dst[n] (which does not necessarily refer to a
     valid memory location.)

EXAMPLES
     The following sets	chararray to "abc\0\0\0":

	   char	chararray[6];

	   (void)strncpy(chararray, "abc", sizeof(chararray));

     The following sets	chararray to "abcdef":

	   char	chararray[6];

	   (void)strncpy(chararray, "abcdefgh",	sizeof(chararray));

     Note that it does not NUL terminate chararray because the length of the
     source string is greater than or equal to the length argument.

     The following copies as many characters from input	to buf as will fit and
     NUL terminates the	result.	 Because strncpy() does	not guarantee to NUL
     terminate the string itself, this must be done explicitly.

	   char	buf[1024];

	   (void)strncpy(buf, input, sizeof(buf) - 1);
	   buf[sizeof(buf) - 1]	= '\0';

     This could	be better achieved using strlcpy(3), as	shown in the following
     example:

	   (void)strlcpy(buf, input, sizeof(buf));

     Note that because strlcpy(3) is not defined in any	standards, it should
     only be used when portability is not a concern.

SEE ALSO
     bcopy(3), memccpy(3), memcpy(3), memmove(3), strlcpy(3), wcscpy(3)

STANDARDS
     The strcpy() and strncpy()	functions conform to ISO/IEC 9899:1990
     ("ISO C90").  The stpcpy()	and stpncpy() functions	conform	to IEEE	Std
     1003.1-2008 ("POSIX.1").

HISTORY
     The stpcpy() function first appeared in FreeBSD 4.4, and stpncpy()	was
     added in FreeBSD 8.0.

SECURITY CONSIDERATIONS
     The strcpy() function is easily misused in	a manner which enables mali-
     cious users to arbitrarily	change a running program's functionality
     through a buffer overflow attack.	(See the FSA and EXAMPLES.)

BSD			       February	28, 2009			   BSD
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | EXAMPLES | SEE ALSO | STANDARDS | HISTORY | SECURITY CONSIDERATIONS

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