apr_snprintf.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

    *len = buf_end - p;
    return (p);
}



static char *conv_in_addr(struct in_addr *ia, char *buf_end, int *len)
{
    unsigned addr = ntohl(ia->s_addr);
    char *p = buf_end;
    bool_int is_negative;
    int sub_len;

    p = conv_10((addr & 0x000000FF)      , TRUE, &is_negative, p, &sub_len);
    *--p = '.';
    p = conv_10((addr & 0x0000FF00) >>  8, TRUE, &is_negative, p, &sub_len);
    *--p = '.';
    p = conv_10((addr & 0x00FF0000) >> 16, TRUE, &is_negative, p, &sub_len);
    *--p = '.';
    p = conv_10((addr & 0xFF000000) >> 24, TRUE, &is_negative, p, &sub_len);

    *len = buf_end - p;
    return (p);
}



static char *conv_apr_sockaddr(apr_sockaddr_t *sa, char *buf_end, int *len)
{
    char *p = buf_end;
    bool_int is_negative;
    int sub_len;
    char *ipaddr_str;

    p = conv_10(sa->port, TRUE, &is_negative, p, &sub_len);
    *--p = ':';
    apr_sockaddr_ip_get(&ipaddr_str, sa);
    sub_len = strlen(ipaddr_str);
#if APR_HAVE_IPV6
    if (sa->family == APR_INET6 &&
        !IN6_IS_ADDR_V4MAPPED(&sa->sa.sin6.sin6_addr)) {
        *(p - 1) = ']';
        p -= sub_len + 2;
        *p = '[';
        memcpy(p + 1, ipaddr_str, sub_len);
    }
    else
#endif
    {
        p -= sub_len;
        memcpy(p, ipaddr_str, sub_len);
    }

    *len = buf_end - p;
    return (p);
}



#if APR_HAS_THREADS
static char *conv_os_thread_t(apr_os_thread_t *tid, char *buf_end, int *len)
{
    union {
        apr_os_thread_t tid;
        apr_uint64_t alignme;
    } u;
    int is_negative;

    u.tid = *tid;
    switch(sizeof(u.tid)) {
    case sizeof(apr_int32_t):
        return conv_10(*(apr_uint32_t *)&u.tid, TRUE, &is_negative, buf_end, len);
    case sizeof(apr_int64_t):
        return conv_10_quad(*(apr_uint64_t *)&u.tid, TRUE, &is_negative, buf_end, len);
    default:
        /* not implemented; stick 0 in the buffer */
        return conv_10(0, TRUE, &is_negative, buf_end, len);
    }
}
#endif



/*
 * Convert a floating point number to a string formats 'f', 'e' or 'E'.
 * The result is placed in buf, and len denotes the length of the string
 * The sign is returned in the is_negative argument (and is not placed
 * in buf).
 */
static char *conv_fp(register char format, register double num,
    boolean_e add_dp, int precision, bool_int *is_negative,
    char *buf, int *len)
{
    register char *s = buf;
    register char *p;
    int decimal_point;
    char buf1[NDIG];

    if (format == 'f')
        p = apr_fcvt(num, precision, &decimal_point, is_negative, buf1);
    else /* either e or E format */
        p = apr_ecvt(num, precision + 1, &decimal_point, is_negative, buf1);

    /*
     * Check for Infinity and NaN
     */
    if (apr_isalpha(*p)) {
        *len = strlen(p);
        memcpy(buf, p, *len + 1);
        *is_negative = FALSE;
        return (buf);
    }

    if (format == 'f') {
        if (decimal_point <= 0) {
            *s++ = '0';
            if (precision > 0) {
                *s++ = '.';
                while (decimal_point++ < 0)
                    *s++ = '0';
            }
            else if (add_dp)
                *s++ = '.';
        }
        else {
            while (decimal_point-- > 0)
                *s++ = *p++;
            if (precision > 0 || add_dp)
                *s++ = '.';
        }
    }
    else {
        *s++ = *p++;
        if (precision > 0 || add_dp)
            *s++ = '.';
    }

    /*
     * copy the rest of p, the NUL is NOT copied
     */
    while (*p)
        *s++ = *p++;

    if (format != 'f') {
        char temp[EXPONENT_LENGTH];        /* for exponent conversion */
        int t_len;
        bool_int exponent_is_negative;

        *s++ = format;                /* either e or E */
        decimal_point--;
        if (decimal_point != 0) {
            p = conv_10((wide_int) decimal_point, FALSE, &exponent_is_negative,
                        &temp[EXPONENT_LENGTH], &t_len);
            *s++ = exponent_is_negative ? '-' : '+';

            /*
             * Make sure the exponent has at least 2 digits
             */
            if (t_len == 1)
                *s++ = '0';
            while (t_len--)
                *s++ = *p++;
        }
        else {
            *s++ = '+';
            *s++ = '0';
            *s++ = '0';
        }
    }

    *len = s - buf;
    return (buf);
}


/*
 * Convert num to a base X number where X is a power of 2. nbits determines X.
 * For example, if nbits is 3, we do base 8 conversion
 * Return value:
 *      a pointer to a string containing the number
 *
 * The caller provides a buffer for the string: that is the buf_end argument
 * which is a pointer to the END of the buffer + 1 (i.e. if the buffer
 * is declared as buf[ 100 ], buf_end should be &buf[ 100 ])
 *
 * As with conv_10, we have a faster version which is used when
 * the number isn't quad size.
 */
static char *conv_p2(register u_wide_int num, register int nbits,
                     char format, char *buf_end, register int *len)
{
    register int mask = (1 << nbits) - 1;
    register char *p = buf_end;
    static const char low_digits[] = "0123456789abcdef";
    static const char upper_digits[] = "0123456789ABCDEF";
    register const char *digits = (format == 'X') ? upper_digits : low_digits;

    do {
        *--p = digits[num & mask];
        num >>= nbits;
    }
    while (num);

    *len = buf_end - p;
    return (p);
}

static char *conv_p2_quad(u_widest_int num, register int nbits,
                     char format, char *buf_end, register int *len)
{
    register int mask = (1 << nbits) - 1;
    register char *p = buf_end;
    static const char low_digits[] = "0123456789abcdef";
    static const char upper_digits[] = "0123456789ABCDEF";
    register const char *digits = (format == 'X') ? upper_digits : low_digits;

    if (num <= ULONG_MAX)
        return(conv_p2((u_wide_int)num, nbits, format, buf_end, len));

    do {
        *--p = digits[num & mask];
        num >>= nbits;
    }
    while (num);

    *len = buf_end - p;
    return (p);
}


/*
 * Do format conversion placing the output in buffer
 */
APR_DECLARE(int) apr_vformatter(int (*flush_func)(apr_vformatter_buff_t *),
    apr_vformatter_buff_t *vbuff, const char *fmt, va_list ap)
{
    register char *sp;
    register char *bep;
    register int cc = 0;
    register int i;

    register char *s = NULL;
    char *q;
    int s_len;

    register int min_width = 0;
    int precision = 0;
    enum {
        LEFT, RIGHT
    } adjust;
    char pad_char;
    char prefix_char;

    double fp_num;
    widest_int i_quad = (widest_int) 0;
    u_widest_int ui_quad;
    wide_int i_num = (wide_int) 0;
    u_wide_int ui_num;

    char num_buf[NUM_BUF_SIZE];
    char char_buf[2];                /* for printing %% and %<unknown> */

    enum var_type_enum {
            IS_QUAD, IS_LONG, IS_SHORT, IS_INT
    };
    enum var_type_enum var_type = IS_INT;

    /*
     * Flag variables
     */
    boolean_e alternate_form;
    boolean_e print_sign;
    boolean_e print_blank;
    boolean_e adjust_precision;
    boolean_e adjust_width;
    bool_int is_negative;

    sp = vbuff->curpos;
    bep = vbuff->endpos;

    while (*fmt) {
        if (*fmt != '%') {
            INS_CHAR(*fmt, sp, bep, cc);
        }
        else {
            /*
             * Default variable settings
             */
            boolean_e print_something = YES;
            adjust = RIGHT;
            alternate_form = print_sign = print_blank = NO;
            pad_char = ' ';
            prefix_char = NUL;

            fmt++;

            /*
             * Try to avoid checking for flags, width or precision
             */
            if (!apr_islower(*fmt)) {
                /*
                 * Recognize flags: -, #, BLANK, +
                 */
                for (;; fmt++) {
                    if (*fmt == '-')
                        adjust = LEFT;
                    else if (*fmt == '+')
                        print_sign = YES;
                    else if (*fmt == '#')
                        alternate_form = YES;
                    else if (*fmt == ' ')
                        print_blank = YES;
                    else if (*fmt == '0')
                        pad_char = '0';
                    else
                        break;
                }

                /*
                 * Check if a width was specified
                 */
                if (apr_isdigit(*fmt)) {
                    STR_TO_DEC(fmt, min_width);
                    adjust_width = YES;
                }
                else if (*fmt == '*') {
                    min_width = va_arg(ap, int);
                    fmt++;
                    adjust_width = YES;
                    if (min_width < 0) {
                        adjust = LEFT;
                        min_width = -min_width;
                    }
                }
                else
                    adjust_width = NO;

                /*
                 * Check if a precision was specified
                 */
                if (*fmt == '.') {
                    adjust_precision = YES;
                    fmt++;
                    if (apr_isdigit(*fmt)) {
                        STR_TO_DEC(fmt, precision);
                    }
                    else if (*fmt == '*') {
                        precision = va_arg(ap, int);
                        fmt++;
                        if (precision < 0)
                            precision = 0;
                    }
                    else
                        precision = 0;
                }
                else
                    adjust_precision = NO;
            }
            else
                adjust_precision = adjust_width = NO;

            /*
             * Modifier check
             */
#if defined(APR_INT64_T_FMT_LEN) && (APR_INT64_T_FMT_LEN == 3)
            if ((*fmt == APR_INT64_T_FMT[0]) &&
                (fmt[1] == APR_INT64_T_FMT[1])) {
#elif defined(APR_INT64_T_FMT_LEN) && (APR_INT64_T_FMT_LEN == 2)
            if (*fmt == APR_INT64_T_FMT[0]) {
#else
            if (strncmp(fmt, APR_INT64_T_FMT, 
                             sizeof(APR_INT64_T_FMT) - 2) == 0) {
#endif
                /* Need to account for trailing 'd' and null in sizeof() */
                var_type = IS_QUAD;
                fmt += (sizeof(APR_INT64_T_FMT) - 2);
            }
            else if (*fmt == 'q') {
                var_type = IS_QUAD;
                fmt++;
            }
            else if (*fmt == 'l') {
                var_type = IS_LONG;
                fmt++;
            }
            else if (*fmt == 'h') {
                var_type = IS_SHORT;
                fmt++;
            }
            else {
                var_type = IS_INT;
            }

            /*
             * Argument extraction and printing.
             * First we determine the argument type.
             * Then, we convert the argument to a string.
             * On exit from the switch, s points to the string that
             * must be printed, s_len has the length of the string
             * The precision requirements, if any, are reflected in s_len.
             *
             * NOTE: pad_char may be set to '0' because of the 0 flag.
             *   It is reset to ' ' by non-numeric formats
             */
            switch (*fmt) {
            case 'u':
                if (var_type == IS_QUAD) {
                    i_quad = va_arg(ap, u_widest_int);
                    s = conv_10_quad(i_quad, 1, &is_negative,
                            &num_buf[NUM_BUF_SIZE], &s_len);
                }
                else {
                    if (var_type == IS_LONG)
                        i_num = (wide_int) va_arg(ap, u_wide_int);
                    else if (var_type == IS_SHORT)
                        i_num = (wide_int) (unsigned short) va_arg(ap, unsigned int);
                    else
                        i_num = (wide_int) va_arg(ap, unsigned int);
                    s = conv_10(i_num, 1, &is_negative,
                            &num_buf[NUM_BUF_SIZE], &s_len);
                }
                FIX_PRECISION(adjust_precision, precision, s, s_len);
                break;

            case 'd':
            case 'i':
                if (var_type == IS_QUAD) {
                    i_quad = va_arg(ap, widest_int);
                    s = conv_10_quad(i_quad, 0, &is_negative,
                            &num_buf[NUM_BUF_SIZE], &s_len);
                }
                else {
                    if (var_type == IS_LONG)
                        i_num = (wide_int) va_arg(ap, wide_int);
                    else if (var_type == IS_SHORT)
                        i_num = (wide_int) (short) va_arg(ap, int);