os-k/kaleid/crtlib/sprintf.c

//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:       *s*printf() family                                            //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K is free software: you can redistribute it and/or modify              //
//  it under the terms of the GNU General Public License as published by      //
//  the Free Software Foundation, either version 3 of the License, or         //
//  any later version.                                                        //
//                                                                            //
//  OS/K is distributed in the hope that it will be useful,                   //
//  but WITHOUT ANY WARRANTY//without even the implied warranty of            //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
//  GNU General Public License for more details.                              //
//                                                                            //
//  You should have received a copy of the GNU General Public License         //
//  along with OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#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;
}