Determines the display width of wide character strings.
Standard C Library (libc.a)
The wcswidth subroutine determines the number of display columns to be occupied by the number of wide characters specified by the N parameter in the string pointed to by the Pwcs parameter. The LC_CTYPE category affects the behavior of the wcswidth subroutine. Fewer than the number of wide characters specified by the N parameter are counted if a null character is encountered first.
| Item | Description |
|---|---|
| N | Specifies the maximum number of wide characters whose display width is to be determined. |
| Pwcs | Contains a pointer to the wide character string. |
The wcswidth subroutine returns the number of display columns to be occupied by the number of wide characters (up to the terminating wide character null) specified by the N parameter (or fewer) in the string pointed to by the Pwcs parameter. A value of zero is returned if the Pwcs parameter is a wide character null pointer or a pointer to a wide character null (that is, Pwcs or *Pwcs is null). If the Pwcs parameter points to an unusable wide character code, -1 is returned.
To find the display column width of a wide character string, use the following:
#include <string.h>
#include <locale.h>
#include <stdlib.h>
main()
{
wchar_t *pwcs;
int retval, n ; (void)setlocale(LC_ALL, "");
/* Let pwcs point to a wide character null terminated
** string. Let n be the number of wide characters whose
** display column width is to be determined.
*/
retval= wcswidth( pwcs, n );
if(retval == -1){
/* Error handling. Invalid wide character code
** encountered in the wide character string pwcs.
*/
}
}