What is wcscat_s in C?

The wcscat_s function

The wcscat_s function is defined in the wchar.h standard library and is used to copy wide characters from one array to another. The structure of the wcscat_s function is as follows:

errno_t wcscat_s(whcar_t * dest, rsize_t destsz, const whchar_t * src);

Parameters

  • dest is a pointer to a null-terminated wide string to append to.
  • src is a pointer to a null-terminated wide string to copy from.
  • destsz is the maximum number of characters to copy.

Return value

  • Zero upon success
  • Non-zero upon error

Example usage of the wcscat_s function

The following code copies characters from one array to another using the wcscat_s function:

#include<stdio.h>
#include<wchar.h>
int main() {
  wchar_t arr_src[] = L"Hello_World";
  wchar_t arr_dest[13];
  wcscat_s(arr_dest, 11, arr_src);
  wprintf(L"arr_dest: %S", arr_dest);
  return 0;
}

Output:

arr_dest: Hello_World

Note: The function above is not supported by the GCC compiler, so you will get an implicit declaration of function… error.

Use the following variant wcscat to get the job done:

wchar_t * wcscat(whcar_t * dest, const whchar_t * src);

All parameters are the same as wcscat_s, except that destsz is not a parameter of wcscat. The return value of wcscat is the pointer to the dest string.

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