Uzbekistan ID Card MRZ Parser

howto.md

ID card parser

Compiling:

gcc id_card_parser.c -o passport_data

Usage:

 ./passport_data $'IUUZBAD9876543210998877554433<\n9506229F7896543XXXUZB<<<<<<<<9\nESHMATOV<<TOSHMAT<<<<<<<<<<<<<'

id_card_parser.c

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

int is_valid_passport_line(const char *line) {
    for (int i = 0; line[i]; i++) {
        if (!(isupper(line[i]) || isdigit(line[i]) || line[i] == '<')) {
            return 0;
        }
    }
    return 1;
}

int parse_dob_gender_country(const char *line2, char *dob, char *gender, char *countryCode) {
    if (strlen(line2) < 10) return 0;

    strncpy(dob, line2, 6);
    dob[6] = '\0';
    *gender = line2[7];

    strncpy(countryCode, line2 + 8, 3);
    countryCode[3] = '\0';

    return 1;
}

void format_date(const char *dob, char *formattedDate) {
    int year = atoi((char[]){dob[0], dob[1], '\0'});
    char fullYear[5];

    if (year <= 21) {
        sprintf(fullYear, "20%02d", year);
    } else {
        sprintf(fullYear, "19%02d", year);
    }

    char month[3] = {dob[2], dob[3], '\0'};
    char day[3] = {dob[4], dob[5], '\0'};

    sprintf(formattedDate, "%s-%s-%s", fullYear, month, day);
}

int parse_name_line(const char *line3, char *lastName, char *firstName) {
    const char *sep = strstr(line3, "<<");
    if (!sep) return 0;

    int lenLast = sep - line3;
    strncpy(lastName, line3, lenLast);
    lastName[lenLast] = '\0';

    const char *firstStart = sep + 2;
    const char *end = strstr(firstStart, "<<");
    if (!end) end = firstStart + strlen(firstStart);

    strncpy(firstName, firstStart, end - firstStart);
    firstName[end - firstStart] = '\0';

    return 1;
}

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: %s $'<passport_text_with_\\n_lines>'\n", argv[0]);
        return 1;
    }

    char *text = argv[1];
    char *line1 = strtok(text, "\n");
    char *line2 = strtok(NULL, "\n");
    char *line3 = strtok(NULL, "\n");

    if (!line1 || !line2 || !line3) {
        printf("Passport data should consist of exactly 3 lines.\n");
        return 1;
    }

    if (!is_valid_passport_line(line1)) {
        printf("Invalid characters in the passport number (Line 1).\n");
        return 1;
    }

    char dob[7], gender, countryCode[4];
    if (!parse_dob_gender_country(line2, dob, &gender, countryCode)) {
        printf("Line 2 is not in the correct format (YYMMDD, gender, country code).\n");
        return 1;
    }

    char formattedDate[11];
    format_date(dob, formattedDate);

    char lastName[50], firstName[50];
    if (!parse_name_line(line3, lastName, firstName)) {
        printf("Line 3 is not in the correct format (LastName<<FirstName).\n");
        return 1;
    }

    printf("Passport Data:\n");
    printf("Passport Number: %s\n", line1);
    printf("Date of Birth: %s\n", formattedDate);
    printf("Gender: %c\n", gender);
    printf("Country Code: %s\n", countryCode);
    printf("Last Name: %s\n", lastName);
    printf("First Name: %s\n", firstName);

    return 0;
}