dmi_date_parse

Synopsis

#include <opendmi/utils/datetime.h>

typedef uint32_t dmi_date_t;

#define DMI_DATE(year, month, day) ...
#define DMI_DATE_NONE DMI_DATE(0, 0, 0)

dmi_date_t dmi_date_parse(const char *str);
char *dmi_date_format(dmi_date_t date);

Description

A date, dmi_date_t, holds the year in its upper 16 bits, the month in the next 8 bits and the day in the lower 8 bits, so that dates compare as integers. The DMI_DATE macro and the dmi_date function make a date of its parts, and the dmi_date_year, dmi_date_month and dmi_date_day functions take them apart. DMI_DATE_NONE, all parts zero, stands for no date.

The dmi_date_parse function parses str as a date of the form SMBIOS gives dates in, e.g. the release date of the firmware: MM/DD/YY or MM/DD/YYYY. The month and the day are numbers of any number of digits, within 1 to 12 and 1 to 31; no further check against the calendar is made, e.g. 02/31/2020 is accepted. A year of two digits is taken as years since 1900, so that 05 is 1905, as the SMBIOS specification has it. A string of more than 10 characters, a part which holds anything but digits, e.g. a sign or a blank, and a year of other than two or four digits are rejected.

The dmi_date_format function formats date as YYYY-MM-DD, the year padded with zeros to four digits, and the month and the day to two, e.g. 2025-03-07. DMI_DATE_NONE is formatted as 0000-00-00. The caller is responsible for freeing the string with free() or dmi_free.

Parameters

str: String to parse.
date: Date to format.

Return value

The dmi_date_parse function returns the date, or DMI_DATE_NONE if str is nullptr or is not a date of the form.

The dmi_date_format function returns a newly allocated string, or nullptr if memory is exhausted.

Errors

DMI_ERROR_ARGUMENT_NULL: Raised by dmi_date_parse if str is nullptr. The functions take no context, so the error reaches no error queue.

Example

dmi_date_t date = dmi_date_parse("03/07/2025");

if (date != DMI_DATE_NONE) {
    char *text = dmi_date_format(date);

    if (text != nullptr) {
        puts(text); // "2025-03-07"
        free(text);
    }
}