STRCPY(3)

NAME
strcpy, strncpy - copy strings

LIBRARY
libc

SYNOPSIS
#include <string.h>
char *
strcpy(char *dst, const char *src);
char *
strncpy(char *dst, const char *src, size_t len);

DESCRIPTION
The strcpy() function copies the string src to dst (including the terminating ‘\0’ character).

The strncpy() function copies not more than len characters from src into dst, appending ‘\0’ characters if src is less than len characters long, and not terminating dst otherwise.

RETURN VALUES
The strcpy() and strncpy() functions return dst.

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 parameter.

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)

STANDARDS
The strcpy() and strncpy() functions conform to isoC.