strncat

SYNOPSIS
       #include <string.h>

       char *strcat(char *dest, const char *src);

       char *strncat(char *dest, const char *src, size_t n);

DESCRIPTION
       The  strcat() function appends the src string to the dest string, over-
       writing the null byte ('\0') at the end of dest, and then adds a termi-
       nating  null  byte.   The  strings may not overlap, and the dest string
       must have enough space for the result.

       The strncat() function is similar, except that

       *  it will use at most n characters from src; and

       *  src does not need to be null terminated if it  contains  n  or  more
          characters.

       As  with  strcat(),  the resulting string in dest is always null termi-
       nated.

       If src contains n or more characters, strncat() writes  n+1  characters
       to  dest  (n  from src plus the terminating null byte).  Therefore, the
       size of dest must be at least strlen(dest)+n+1.

       A simple implementation of strncat() might be:

           char*
           strncat(char *dest, const char *src, size_t n)
           {
               size_t dest_len = strlen(dest);
               size_t i;

               for (i = 0 ; i < n && src[i] != '\0' ; i++)
                   dest[dest_len + i] = src[i];
               dest[dest_len + i] = '\0';

               return dest;
           }

RETURN VALUE
       The strcat() and strncat() functions return a pointer to the  resulting
       string dest.

CONFORMING TO
       SVr4, 4.3BSD, C89, C99.

SEE ALSO
       bcopy(3),  memccpy(3),  memcpy(3),  strcpy(3),  strncpy(3),  wcscat(3),
       wcsncat(3)