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STRCPY(3)		     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  strcpy()  and stpcpy() functions copy the string src to dst (including
     the terminating `\0' character.)

     The strncpy() and stpncpy() 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.

     For  all of strcpy(), strncpy(), stpcpy(), and stpncpy(), the result is un-
     defined if src and dst overlap.

RETURN VALUES
     The strcpy() and strncpy() functions return dst.	The  stpcpy()  and  stp-
     ncpy() functions return a pointer to the terminating `\0' character of dst.
     If  stpncpy()  does  not terminate dst with a NUL character, it instead re-
     turns a pointer to dst[n] (which does not necessarily refer to a valid mem-
     ory 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));

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
     All of the functions documented in this manual page are easily misused in a
     manner  which  enables malicious users to arbitrarily change a running pro-
     gram's functionality through a buffer overflow attack.

     It is strongly suggested that the strlcpy() function be used in almost  all
     cases.

     For  some, but not all, fixed-length records, non-terminated strings may be
     both valid and desirable.	In that specific case,	the  strncpy()	function
     may be most sensible.

FreeBSD ports 15.1		  June 6, 2018			       STRCPY(3)

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