適当な一文字を返す関数、C言語版

適当なAscii文字を返す関数。たまに使うからメモ書き

static short _createRandomCharaFlag = 0;
char createRandamCharactor ()
{
    char ch = 0x00;

    if (_createRandomCharaFlag == 0) {
        srand((unsigned)time(NULL));
        _createRandomCharaFlag = 1;
    }

    while (1) {
        int j = rand() & 0x7f;
        if (j >= 0x30 && j <= 0x7a)
            return (char)j;
    }
    return ch;
}