os-k/kaleid/crtlib/sprintf.c

//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Authors:    spectral`                                                     //
//              NeoX                                                          //
//                                                                            //
//  Desc:       sprintf()-related functions                                   //
//----------------------------------------------------------------------------//

#include <kalbase.h>

//
// Format str according to fmt using ellipsed arguments
//
// BE CAREFUL when using this
// you need to know for sure an overflow won't happen
//
int sprintf(char *str, const char *fmt, ...)
{
    int ret;
    va_list ap;

    va_start(ap);
    ret = vsnprintf(str, SIZE_T_MAX, fmt, ap);
    va_end(ap);

    return ret;
}

int vsprintf(char *str, const char *fmt, va_list ap)
{
    return vsnprintf(str, SIZE_T_MAX, fmt, ap);
}

//
// (v)sprintf() but with a size limit: no more than n bytes are written in str
// Always null-terminate str
//
int snprintf(char *str, size_t n, const char *fmt, ...)
{
    int ret;
    va_list ap;

    va_start(ap);
    ret = vsnprintf(str, n, fmt, ap)
    va_end(ap);

    return ret;
}

int vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
{
    int ret = 0;

    //
    // Go throught the format string
    //
    while (*fmt) {
        if (*fmt != '%') {
            //
            // Even if we don't have any more room we still increase ret
            //
            if (ret++ < n) {
                *str++ = *fmt++;
            }
            continue;
        }

        switch (*fmt) {
            case 'd':
            default:
            break;
        }
    }

    return ret;
}