tuklib_mbstr_fw.c File Reference

Get the field width for printf() e.g. to align table columns. More...

#include "tuklib_mbstr.h"

Go to the source code of this file.

Functions
int	tuklib_mbstr_fw (const char *str, int columns_min)
	Get the field width for printf() e.g. to align table columns. More...

Detailed Description

Get the field width for printf() e.g. to align table columns.

Definition in file tuklib_mbstr_fw.c.

Function Documentation

tuklib_mbstr_fw()

int tuklib_mbstr_fw	(	const char *	str,
		int	columns_min
	)

Get the field width for printf() e.g. to align table columns.

Printing simple tables to a terminal can be done using the field field feature in the printf() format string, but it works only with single-byte character sets. To do the same with multibyte strings, tuklib_mbstr_fw() can be used to calculate appropriate field width.

The behavior of this function is undefined, if

• str is NULL or not terminated with '\0';
• columns_min <= 0; or
• the calculated field width exceeds INT_MAX.

Returns

If tuklib_mbstr_width(str, NULL) fails, -1 is returned. If str needs more columns than columns_min, zero is returned. Otherwise a positive integer is returned, which can be used as the field width, e.g. printf("%*s", fw, str).

Definition at line 17 of file tuklib_mbstr_fw.c.

{
    size_t len;
    const size_t width = tuklib_mbstr_width(str, &len);
    if (width == (size_t)-1)
        return -1;
 
    if (width > (size_t)columns_min)
        return 0;
 
    if (width < (size_t)columns_min)
        len += (size_t)columns_min - width;
 
    return len;
}

References len, cmd_descs_generate::str, tuklib_mbstr_width, and width.