WCWIDTH(3) Linux Programmer's Manual WCWIDTH(3)

wcwidth - determine columns needed for a wide character

#define _XOPEN_SOURCE       /* See feature_test_macros(7) */
#include <wchar.h>
int wcwidth(wchar_t c);

The wcwidth() function returns the number of columns needed to represent the wide character c. If c is a printable wide character, the value is at least 0. If c is null wide character (L'\0'), the value is 0. Otherwise, -1 is returned.

The wcwidth() function returns the number of column positions for c.

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
wcwidth () Thread safety MT-Safe locale

POSIX.1-2001, POSIX.1-2008.
Note that glibc before 2.2.5 used the prototype
int wcwidth(wint_t c);

The behavior of wcwidth() depends on the LC_CTYPE category of the current locale.

iswprint(3), wcswidth(3)
2019-03-06 GNU